diff --git a/src/features/agent-graph/renderer/adapters/TeamGraphAdapter.ts b/src/features/agent-graph/renderer/adapters/TeamGraphAdapter.ts
index ce88d46c..d805172b 100644
--- a/src/features/agent-graph/renderer/adapters/TeamGraphAdapter.ts
+++ b/src/features/agent-graph/renderer/adapters/TeamGraphAdapter.ts
@@ -677,19 +677,60 @@ export class TeamGraphAdapter {
   ): void {
     const taskStateById = new Map<
       string,
-      Pick<TeamGraphData['tasks'][number], 'status' | 'reviewState' | 'kanbanColumn' | 'deletedAt'>
+      Pick<
+        TeamGraphData['tasks'][number],
+        'id' | 'displayId' | 'status' | 'reviewState' | 'kanbanColumn' | 'deletedAt'
+      >
     >();
     const taskDisplayIds = new Map<string, string>();
+    const taskIdsByCanonicalReference = new Map<string, Set<string>>();
+    const taskIdsByDisplayReference = new Map<string, Set<string>>();
     const memberColorByName = new Map<string, string>();
+    const addTaskReference = (
+      references: Map<string, Set<string>>,
+      reference: string | undefined,
+      taskId: string
+    ): void => {
+      const normalized = reference?.trim().replace(/^#/, '');
+      if (!normalized) return;
+      const taskIds = references.get(normalized) ?? new Set<string>();
+      taskIds.add(taskId);
+      references.set(normalized, taskIds);
+    };
+    const resolveTaskReference = (reference: string): string | null => {
+      const normalized = reference.trim().replace(/^#/, '');
+      if (!normalized) return null;
+      const canonicalTaskIds = taskIdsByCanonicalReference.get(normalized);
+      if (canonicalTaskIds?.size === 1) {
+        return [...canonicalTaskIds][0]!;
+      }
+      if (canonicalTaskIds && canonicalTaskIds.size > 1) {
+        return null;
+      }
+      const displayTaskIds = taskIdsByDisplayReference.get(normalized);
+      return displayTaskIds?.size === 1 ? [...displayTaskIds][0]! : null;
+    };
+    const formatTaskReference = (reference: string): string => {
+      const taskId = resolveTaskReference(reference);
+      if (taskId) {
+        return taskDisplayIds.get(taskId) ?? `#${taskId.slice(0, 6)}`;
+      }
+      const trimmed = reference.trim();
+      return trimmed.startsWith('#') ? trimmed : `#${trimmed.slice(0, 6)}`;
+    };
 
     for (const t of data.tasks) {
       taskStateById.set(t.id, {
+        id: t.id,
+        ...(t.displayId ? { displayId: t.displayId } : {}),
         status: t.status,
         ...(t.reviewState ? { reviewState: t.reviewState } : {}),
         ...(t.kanbanColumn ? { kanbanColumn: t.kanbanColumn } : {}),
         ...(t.deletedAt ? { deletedAt: t.deletedAt } : {}),
       });
       taskDisplayIds.set(t.id, t.displayId ?? `#${t.id.slice(0, 6)}`);
+      addTaskReference(taskIdsByCanonicalReference, t.id, t.id);
+      addTaskReference(taskIdsByDisplayReference, t.displayId, t.id);
     }
     for (const member of data.members) {
       if (member.color) {
@@ -726,10 +767,10 @@ export class TeamGraphAdapter {
             : TeamGraphAdapter.#mapReviewState(task.reviewState);
 
       const blockedByDisplayIds = task.blockedBy?.length
-        ? task.blockedBy.map((id) => taskDisplayIds.get(id) ?? `#${id.slice(0, 6)}`)
+        ? task.blockedBy.map(formatTaskReference)
         : undefined;
       const blocksDisplayIds = task.blocks?.length
-        ? task.blocks.map((id) => taskDisplayIds.get(id) ?? `#${id.slice(0, 6)}`)
+        ? task.blocks.map(formatTaskReference)
         : undefined;
 
       const totalCommentCount = task.comments?.length ?? 0;
@@ -799,7 +840,10 @@ export class TeamGraphAdapter {
         targetTaskIds: Set<string>;
       }
     >();
-    const addBlockingRelation = (blockerId: string, blockedId: string): void => {
+    const addBlockingRelation = (blockerRef: string, blockedRef: string): void => {
+      const blockerId = resolveTaskReference(blockerRef);
+      const blockedId = resolveTaskReference(blockedRef);
+      if (!blockerId || !blockedId) return;
       if (blockerId === blockedId) return;
       const rawRelationKey = `${blockerId}->${blockedId}`;
       if (seenBlockingRelations.has(rawRelationKey)) return;
@@ -842,7 +886,9 @@ export class TeamGraphAdapter {
 
       if (!visibleTaskIds.has(task.id)) continue;
 
-      for (const relatedId of task.related ?? []) {
+      for (const relatedRef of task.related ?? []) {
+        const relatedId = resolveTaskReference(relatedRef);
+        if (!relatedId) continue;
         if (!visibleTaskIds.has(relatedId)) continue;
         const key =
           task.id.localeCompare(relatedId) <= 0
diff --git a/src/features/member-work-sync/core/domain/ActionableWorkAgenda.ts b/src/features/member-work-sync/core/domain/ActionableWorkAgenda.ts
index dd457aef..9bc2f2e7 100644
--- a/src/features/member-work-sync/core/domain/ActionableWorkAgenda.ts
+++ b/src/features/member-work-sync/core/domain/ActionableWorkAgenda.ts
@@ -90,11 +90,47 @@ function buildBaseItem(
   };
 }
 
-function taskReferenceKeys(task: Pick<MemberWorkSyncTaskLike, 'id' | 'displayId'>): string[] {
-  const keys = [task.id, task.displayId]
-    .map((value) => value?.trim())
-    .filter((value): value is string => Boolean(value));
-  return [...new Set(keys.flatMap((value) => [value, value.replace(/^#/, '')]))];
+interface TaskReferenceIndex {
+  canonical: Map<string, Set<MemberWorkSyncTaskLike>>;
+  display: Map<string, Set<MemberWorkSyncTaskLike>>;
+}
+
+function addTaskReference(
+  index: Map<string, Set<MemberWorkSyncTaskLike>>,
+  reference: string | undefined,
+  task: MemberWorkSyncTaskLike
+): void {
+  const normalized = reference?.trim().replace(/^#/, '');
+  if (!normalized) return;
+  const matches = index.get(normalized) ?? new Set<MemberWorkSyncTaskLike>();
+  matches.add(task);
+  index.set(normalized, matches);
+}
+
+function buildTaskReferenceIndex(tasks: MemberWorkSyncTaskLike[]): TaskReferenceIndex {
+  const index = new Map<string, Set<MemberWorkSyncTaskLike>>();
+  const display = new Map<string, Set<MemberWorkSyncTaskLike>>();
+  for (const task of tasks) {
+    addTaskReference(index, task.id, task);
+    addTaskReference(display, task.displayId, task);
+  }
+  return { canonical: index, display };
+}
+
+function findUniqueReferencedTask(
+  tasksByReference: TaskReferenceIndex,
+  reference: string
+): MemberWorkSyncTaskLike | null {
+  const normalized = reference.trim().replace(/^#/, '');
+  const canonicalMatches = tasksByReference.canonical.get(normalized);
+  if (canonicalMatches?.size === 1) {
+    return [...canonicalMatches][0]!;
+  }
+  if (canonicalMatches && canonicalMatches.size > 1) {
+    return null;
+  }
+  const matches = tasksByReference.display.get(normalized);
+  return matches?.size === 1 ? [...matches][0]! : null;
 }
 
 export function buildActionableWorkAgenda(
@@ -104,9 +140,7 @@ export function buildActionableWorkAgenda(
   const diagnostics: string[] = [];
   const activeMemberNames = getActiveMemberNames(input.members);
   const activeLeadName = getActiveLeadName(input.members);
-  const tasksByReference = new Map(
-    input.tasks.flatMap((task) => taskReferenceKeys(task).map((key) => [key, task] as const))
-  );
+  const tasksByReference = buildTaskReferenceIndex(input.tasks);
 
   if (!memberName || isReservedMemberName(memberName)) {
     diagnostics.push('member_invalid_or_reserved');
@@ -135,7 +169,7 @@ export function buildActionableWorkAgenda(
       const brokenDependencyIds: string[] = [];
       const waitingDependencyIds: string[] = [];
       for (const dependencyId of blockedBy) {
-        const dependency = tasksByReference.get(dependencyId) ?? null;
+        const dependency = findUniqueReferencedTask(tasksByReference, dependencyId);
         if (!dependency || dependency.status === 'deleted' || dependency.deletedAt) {
           brokenDependencyIds.push(dependencyId);
         } else if (!isTeamTaskFinishedForDependency(dependency)) {
diff --git a/src/features/member-work-sync/main/adapters/input/MemberWorkSyncTaskImpactResolver.ts b/src/features/member-work-sync/main/adapters/input/MemberWorkSyncTaskImpactResolver.ts
index b6f0fae7..b0d74322 100644
--- a/src/features/member-work-sync/main/adapters/input/MemberWorkSyncTaskImpactResolver.ts
+++ b/src/features/member-work-sync/main/adapters/input/MemberWorkSyncTaskImpactResolver.ts
@@ -32,22 +32,65 @@ function isDeletedTask(task: Pick<TeamTask, 'status' | 'deletedAt'>): boolean {
   return task.status === 'deleted' || Boolean(task.deletedAt);
 }
 
-function taskMatchesId(task: TeamTask, taskId: string): boolean {
-  const normalized = taskId.trim().replace(/^#/, '');
+interface TaskReferenceIndex {
+  canonical: Map<string, Set<TeamTask>>;
+  display: Map<string, Set<TeamTask>>;
+}
+
+function addTaskReference(
+  index: Map<string, Set<TeamTask>>,
+  reference: string | undefined,
+  task: TeamTask
+): void {
+  const normalized = reference?.trim().replace(/^#/, '');
+  if (!normalized) return;
+  const matches = index.get(normalized) ?? new Set<TeamTask>();
+  matches.add(task);
+  index.set(normalized, matches);
+}
+
+function buildTaskReferenceIndex(tasks: TeamTask[]): TaskReferenceIndex {
+  const canonical = new Map<string, Set<TeamTask>>();
+  const display = new Map<string, Set<TeamTask>>();
+  for (const task of tasks) {
+    addTaskReference(canonical, task.id, task);
+    addTaskReference(display, task.displayId, task);
+  }
+  return { canonical, display };
+}
+
+function getTaskReferenceMatches(
+  tasksByReference: TaskReferenceIndex,
+  reference: string
+): ReadonlySet<TeamTask> | null {
+  const normalized = reference.trim().replace(/^#/, '');
   return (
-    task.id === taskId ||
-    task.id === normalized ||
-    task.displayId === taskId ||
-    task.displayId === normalized ||
-    task.displayId === `#${normalized}`
+    tasksByReference.canonical.get(normalized) ?? tasksByReference.display.get(normalized) ?? null
   );
 }
 
-function taskReferenceKeys(task: Pick<TeamTask, 'id' | 'displayId'>): string[] {
-  const keys = [task.id, task.displayId]
-    .map((value) => value?.trim())
-    .filter((value): value is string => Boolean(value));
-  return [...new Set(keys.flatMap((value) => [value, value.replace(/^#/, '')]))];
+function taskReferenceIncludesTask(
+  tasksByReference: TaskReferenceIndex,
+  reference: string,
+  task: TeamTask
+): boolean {
+  return getTaskReferenceMatches(tasksByReference, reference)?.has(task) === true;
+}
+
+function taskReferenceIsMissingOrDeleted(
+  tasksByReference: TaskReferenceIndex,
+  reference: string
+): boolean {
+  const matches = getTaskReferenceMatches(tasksByReference, reference);
+  if (!matches || matches.size === 0) {
+    return true;
+  }
+  return [...matches].every(isDeletedTask);
+}
+
+function findTasksByReference(tasksByReference: TaskReferenceIndex, reference: string): TeamTask[] {
+  const matches = getTaskReferenceMatches(tasksByReference, reference);
+  return matches ? [...matches] : [];
 }
 
 function normalizedTaskReferences(values: readonly string[] | undefined): string[] {
@@ -124,14 +167,23 @@ export class MemberWorkSyncTaskImpactResolver {
       }
     };
 
-    const task = tasks.find((candidate) => taskMatchesId(candidate, taskId));
-    if (!task) {
+    const tasksByReference = buildTaskReferenceIndex(tasks);
+    const matchingTasks = findTasksByReference(tasksByReference, taskId);
+    if (matchingTasks.length === 0) {
       return {
         memberNames: [],
         fallbackTeamWide: true,
         diagnostics: ['task_not_found'],
       };
     }
+    if (matchingTasks.length > 1) {
+      return {
+        memberNames: [],
+        fallbackTeamWide: true,
+        diagnostics: ['task_reference_ambiguous'],
+      };
+    }
+    const task = matchingTasks[0]!;
 
     addMember(task.owner);
 
@@ -178,14 +230,8 @@ export class MemberWorkSyncTaskImpactResolver {
       addLead();
     }
 
-    const tasksByReference = new Map(
-      tasks.flatMap((candidate) =>
-        taskReferenceKeys(candidate).map((key) => [key, candidate] as const)
-      )
-    );
     const brokenDependencies = normalizedTaskReferences(task.blockedBy).filter((dependencyId) => {
-      const dependency = tasksByReference.get(dependencyId);
-      return !dependency || isDeletedTask(dependency);
+      return taskReferenceIsMissingOrDeleted(tasksByReference, dependencyId);
     });
     if (brokenDependencies.length > 0) {
       addLead();
@@ -204,8 +250,8 @@ export class MemberWorkSyncTaskImpactResolver {
         continue;
       }
       if (
-        normalizedTaskReferences(candidate.blockedBy).some(
-          (dependencyId) => tasksByReference.get(dependencyId) === task
+        normalizedTaskReferences(candidate.blockedBy).some((dependencyId) =>
+          taskReferenceIncludesTask(tasksByReference, dependencyId, task)
         )
       ) {
         addMember(candidate.owner);
diff --git a/src/shared/utils/teamTaskState.ts b/src/shared/utils/teamTaskState.ts
index aa47133f..8fd42254 100644
--- a/src/shared/utils/teamTaskState.ts
+++ b/src/shared/utils/teamTaskState.ts
@@ -1,4 +1,6 @@
 export interface TeamTaskStateLike {
+  id?: string | null;
+  displayId?: string | null;
   status: string;
   reviewState?: string | null;
   kanbanColumn?: string | null;
@@ -126,6 +128,55 @@ export function isTeamTaskFinishedForDependency(task: TeamTaskStateLike): boolea
   return getCachedTeamTaskState(task).finishedForDependency;
 }
 
+function normalizeTaskReference(value: unknown): string {
+  return typeof value === 'string' ? value.trim().replace(/^#/, '') : '';
+}
+
+function findTaskStateByReference(
+  taskStateById: ReadonlyMap<string, TeamTaskStateLike>,
+  taskId: string
+): TeamTaskStateLike | null {
+  const normalized = normalizeTaskReference(taskId);
+  if (!normalized) {
+    return null;
+  }
+
+  const direct =
+    taskStateById.get(taskId) ??
+    taskStateById.get(normalized) ??
+    taskStateById.get(`#${normalized}`);
+  if (direct && (!direct.id || normalizeTaskReference(direct.id) === normalized)) {
+    return direct;
+  }
+
+  let idMatched: TeamTaskStateLike | null = null;
+  for (const task of taskStateById.values()) {
+    if (normalizeTaskReference(task.id) === normalized) {
+      if (idMatched && idMatched !== task) {
+        return null;
+      }
+      idMatched = task;
+    }
+  }
+  if (idMatched) {
+    return idMatched;
+  }
+
+  let displayMatched: TeamTaskStateLike | null = null;
+  for (const [key, task] of taskStateById) {
+    if (
+      normalizeTaskReference(key) === normalized ||
+      normalizeTaskReference(task.displayId) === normalized
+    ) {
+      if (displayMatched && displayMatched !== task) {
+        return null;
+      }
+      displayMatched = task;
+    }
+  }
+  return displayMatched;
+}
+
 export function isTeamTaskBlockedByUnfinishedDependency(
   task: TeamTaskBlockerLike,
   taskStateById: ReadonlyMap<string, TeamTaskStateLike>
@@ -137,7 +188,7 @@ export function isTeamTaskBlockedByUnfinishedDependency(
   }
 
   return blockedBy.some((taskId) => {
-    const blocker = taskStateById.get(taskId);
+    const blocker = findTaskStateByReference(taskStateById, taskId);
     return !blocker || (!isTeamTaskFinishedForDependency(blocker) && !isTeamTaskDeleted(blocker));
   });
 }
diff --git a/test/features/member-work-sync/core/ActionableWorkAgenda.test.ts b/test/features/member-work-sync/core/ActionableWorkAgenda.test.ts
index 1423f424..f4ad5e28 100644
--- a/test/features/member-work-sync/core/ActionableWorkAgenda.test.ts
+++ b/test/features/member-work-sync/core/ActionableWorkAgenda.test.ts
@@ -709,6 +709,78 @@ describe('buildActionableWorkAgenda', () => {
     expect(agenda.items).toEqual([]);
   });
 
+  it('does not unblock owner work when a display-id dependency is ambiguous', () => {
+    const agenda = buildActionableWorkAgenda({
+      teamName: 'team-a',
+      memberName: 'bob',
+      generatedAt: '2026-04-29T00:00:00.000Z',
+      members: [{ name: 'bob' }],
+      tasks: [
+        {
+          id: 'task-active-dep',
+          displayId: '#33333333',
+          subject: 'Active dependency',
+          status: 'in_progress',
+          owner: 'alice',
+        },
+        {
+          id: 'task-completed-dep',
+          displayId: '#33333333',
+          subject: 'Duplicate completed dependency',
+          status: 'completed',
+          owner: 'alice',
+        },
+        {
+          id: 'task-dependent',
+          subject: 'Ambiguous dependency',
+          status: 'in_progress',
+          owner: 'bob',
+          blockedBy: ['33333333'],
+        },
+      ],
+      hash,
+    });
+
+    expect(agenda.items).toEqual([]);
+  });
+
+  it('prefers canonical task ids over colliding display ids for dependencies', () => {
+    const agenda = buildActionableWorkAgenda({
+      teamName: 'team-a',
+      memberName: 'bob',
+      generatedAt: '2026-04-29T00:00:00.000Z',
+      members: [{ name: 'bob' }],
+      tasks: [
+        {
+          id: 'task-dep',
+          displayId: '#33333333',
+          subject: 'Completed dependency',
+          status: 'completed',
+          owner: 'alice',
+        },
+        {
+          id: 'task-collision',
+          displayId: '#task-dep',
+          subject: 'Display collision',
+          status: 'in_progress',
+          owner: 'alice',
+        },
+        {
+          id: 'task-dependent',
+          subject: 'Canonical dependency',
+          status: 'in_progress',
+          owner: 'bob',
+          blockedBy: ['task-dep'],
+        },
+      ],
+      hash,
+    });
+
+    expect(agenda.items.map((item) => [item.taskId, item.reason])).toEqual([
+      ['task-dependent', 'owned_in_progress_task'],
+    ]);
+  });
+
   it('projects lead-owned oversight for lead clarification and broken dependencies', () => {
     const agenda = buildActionableWorkAgenda({
       teamName: 'team-a',
diff --git a/test/features/member-work-sync/main/MemberWorkSyncTaskImpactResolver.test.ts b/test/features/member-work-sync/main/MemberWorkSyncTaskImpactResolver.test.ts
index 31b7319b..7075fff1 100644
--- a/test/features/member-work-sync/main/MemberWorkSyncTaskImpactResolver.test.ts
+++ b/test/features/member-work-sync/main/MemberWorkSyncTaskImpactResolver.test.ts
@@ -129,6 +129,116 @@ describe('MemberWorkSyncTaskImpactResolver', () => {
     });
   });
 
+  it('targets dependent owners when a display-id dependency is ambiguous but includes the changed task', async () => {
+    const tasks: TeamTask[] = [
+      {
+        id: 'task-a',
+        displayId: '#11111111',
+        subject: 'Changed dependency',
+        status: 'in_progress',
+        owner: 'alice',
+      },
+      {
+        id: 'task-duplicate',
+        displayId: '#11111111',
+        subject: 'Duplicate display id',
+        status: 'completed',
+        owner: 'zoe',
+      },
+      {
+        id: 'task-b',
+        subject: 'Depends on ambiguous display id',
+        status: 'pending',
+        owner: 'tom',
+        blockedBy: [' 11111111 '],
+      },
+    ];
+    const resolver = new MemberWorkSyncTaskImpactResolver({
+      taskReader: { getTasks: vi.fn(async () => tasks) },
+      kanbanManager: { getState: vi.fn(async () => ({ tasks: {} })) },
+      activeMemberSource: {
+        loadActiveMemberNames: vi.fn(async () => ['alice', 'team-lead', 'tom', 'zoe']),
+      },
+    } as never);
+
+    await expect(resolver.resolve({ teamName: 'team-a', taskId: 'task-a' })).resolves.toEqual({
+      memberNames: ['alice', 'tom'],
+      fallbackTeamWide: false,
+      diagnostics: [],
+    });
+  });
+
+  it('falls back team-wide when the changed task reference is ambiguous', async () => {
+    const tasks: TeamTask[] = [
+      {
+        id: 'task-a',
+        displayId: '#11111111',
+        subject: 'First duplicate',
+        status: 'in_progress',
+        owner: 'alice',
+      },
+      {
+        id: 'task-b',
+        displayId: '#11111111',
+        subject: 'Second duplicate',
+        status: 'pending',
+        owner: 'tom',
+      },
+    ];
+    const resolver = new MemberWorkSyncTaskImpactResolver({
+      taskReader: { getTasks: vi.fn(async () => tasks) },
+      kanbanManager: { getState: vi.fn(async () => ({ tasks: {} })) },
+      activeMemberSource: {
+        loadActiveMemberNames: vi.fn(async () => ['alice', 'team-lead', 'tom']),
+      },
+    } as never);
+
+    await expect(resolver.resolve({ teamName: 'team-a', taskId: '#11111111' })).resolves.toEqual({
+      memberNames: [],
+      fallbackTeamWide: true,
+      diagnostics: ['task_reference_ambiguous'],
+    });
+  });
+
+  it('prefers canonical task ids over colliding display ids', async () => {
+    const tasks: TeamTask[] = [
+      {
+        id: 'task-a',
+        displayId: '#11111111',
+        subject: 'Changed dependency',
+        status: 'completed',
+        owner: 'alice',
+      },
+      {
+        id: 'task-collision',
+        displayId: '#task-a',
+        subject: 'Display collision',
+        status: 'in_progress',
+        owner: 'zoe',
+      },
+      {
+        id: 'task-b',
+        subject: 'Depends on canonical id',
+        status: 'pending',
+        owner: 'tom',
+        blockedBy: ['task-a'],
+      },
+    ];
+    const resolver = new MemberWorkSyncTaskImpactResolver({
+      taskReader: { getTasks: vi.fn(async () => tasks) },
+      kanbanManager: { getState: vi.fn(async () => ({ tasks: {} })) },
+      activeMemberSource: {
+        loadActiveMemberNames: vi.fn(async () => ['alice', 'team-lead', 'tom', 'zoe']),
+      },
+    } as never);
+
+    await expect(resolver.resolve({ teamName: 'team-a', taskId: 'task-a' })).resolves.toEqual({
+      memberNames: ['alice', 'tom'],
+      fallbackTeamWide: false,
+      diagnostics: [],
+    });
+  });
+
   it('does not target owners of already approved dependent tasks', async () => {
     const tasks: TeamTask[] = [
       {
diff --git a/test/main/services/team/teamTaskActiveState.test.ts b/test/main/services/team/teamTaskActiveState.test.ts
index e9752045..d7cd5157 100644
--- a/test/main/services/team/teamTaskActiveState.test.ts
+++ b/test/main/services/team/teamTaskActiveState.test.ts
@@ -142,6 +142,121 @@ describe('isTeamTaskBlockedByUnfinishedDependency', () => {
       isTeamTaskBlockedByUnfinishedDependency({ blockedBy: ['missing'] }, taskStateById)
     ).toBe(true);
   });
+
+  it('resolves blocker references by display id and #display id', () => {
+    const taskStateById = new Map([
+      [
+        'task-completed',
+        {
+          id: 'task-completed',
+          displayId: 'abc12345',
+          status: 'completed',
+        },
+      ],
+      [
+        'task-approved',
+        {
+          id: 'task-approved',
+          displayId: 'def67890',
+          status: 'in_progress',
+          kanbanColumn: 'approved',
+        },
+      ],
+      [
+        'task-active',
+        {
+          id: 'task-active',
+          displayId: 'fedcba98',
+          status: 'in_progress',
+        },
+      ],
+    ]);
+
+    expect(
+      isTeamTaskBlockedByUnfinishedDependency(
+        { blockedBy: ['abc12345', '#def67890'] },
+        taskStateById
+      )
+    ).toBe(false);
+    expect(
+      isTeamTaskBlockedByUnfinishedDependency({ blockedBy: ['#fedcba98'] }, taskStateById)
+    ).toBe(true);
+  });
+
+  it('fails closed for ambiguous display id blocker references', () => {
+    const taskStateById = new Map([
+      [
+        'task-completed',
+        {
+          id: 'task-completed',
+          displayId: 'abc12345',
+          status: 'completed',
+        },
+      ],
+      [
+        'task-active',
+        {
+          id: 'task-active',
+          displayId: 'abc12345',
+          status: 'in_progress',
+        },
+      ],
+    ]);
+
+    expect(
+      isTeamTaskBlockedByUnfinishedDependency({ blockedBy: ['#abc12345'] }, taskStateById)
+    ).toBe(true);
+  });
+
+  it('fails closed when a direct map key match is an ambiguous display id', () => {
+    const taskStateById = new Map([
+      [
+        'abc12345',
+        {
+          id: 'task-completed',
+          displayId: 'abc12345',
+          status: 'completed',
+        },
+      ],
+      [
+        'task-active',
+        {
+          id: 'task-active',
+          displayId: 'abc12345',
+          status: 'in_progress',
+        },
+      ],
+    ]);
+
+    expect(
+      isTeamTaskBlockedByUnfinishedDependency({ blockedBy: ['abc12345'] }, taskStateById)
+    ).toBe(true);
+  });
+
+  it('prefers canonical id matches over colliding display ids', () => {
+    const taskStateById = new Map([
+      [
+        'task-completed',
+        {
+          id: 'task-completed',
+          displayId: 'abc12345',
+          status: 'completed',
+        },
+      ],
+      [
+        'task-active',
+        {
+          id: 'task-active',
+          displayId: 'task-completed',
+          status: 'in_progress',
+        },
+      ],
+    ]);
+
+    expect(
+      isTeamTaskBlockedByUnfinishedDependency({ blockedBy: ['task-completed'] }, taskStateById)
+    ).toBe(false);
+  });
 });
 
 describe('getTeamTaskWorkflowColumn', () => {
diff --git a/test/renderer/features/agent-graph/TeamGraphAdapter.test.ts b/test/renderer/features/agent-graph/TeamGraphAdapter.test.ts
index 99fd1cf8..fa27fd3b 100644
--- a/test/renderer/features/agent-graph/TeamGraphAdapter.test.ts
+++ b/test/renderer/features/agent-graph/TeamGraphAdapter.test.ts
@@ -2112,6 +2112,91 @@ describe('TeamGraphAdapter particles', () => {
     expect(findNode(completedGraph, 'task:my-team:task-b')?.isBlocked).toBe(false);
   });
 
+  it('resolves blocking edges and labels from display id references', () => {
+    const adapter = TeamGraphAdapter.create();
+    const graph = adapter.adapt(
+      createBaseTeamData({
+        tasks: [
+          {
+            id: 'task-a',
+            displayId: '#A1',
+            subject: 'Blocker',
+            owner: 'alice',
+            status: 'in_progress',
+            reviewState: 'none',
+          } as TeamTaskWithKanban,
+          {
+            id: 'task-b',
+            displayId: '#B1',
+            subject: 'Blocked task',
+            owner: 'bob',
+            status: 'pending',
+            blockedBy: ['#A1'],
+            reviewState: 'none',
+          } as TeamTaskWithKanban,
+        ],
+      }),
+      'my-team'
+    );
+
+    expect(findNode(graph, 'task:my-team:task-b')).toMatchObject({
+      isBlocked: true,
+      blockedByDisplayIds: ['#A1'],
+    });
+    expect(graph.edges).toContainEqual(
+      expect.objectContaining({
+        source: 'task:my-team:task-a',
+        target: 'task:my-team:task-b',
+        type: 'blocking',
+      })
+    );
+  });
+
+  it('prefers canonical task ids over colliding display id references', () => {
+    const adapter = TeamGraphAdapter.create();
+    const graph = adapter.adapt(
+      createBaseTeamData({
+        tasks: [
+          {
+            id: 'task-a',
+            displayId: '#A1',
+            subject: 'Canonical blocker',
+            owner: 'alice',
+            status: 'completed',
+            reviewState: 'none',
+          } as TeamTaskWithKanban,
+          {
+            id: 'task-collision',
+            displayId: '#task-a',
+            subject: 'Display id collision',
+            owner: 'alice',
+            status: 'in_progress',
+            reviewState: 'none',
+          } as TeamTaskWithKanban,
+          {
+            id: 'task-b',
+            displayId: '#B1',
+            subject: 'Blocked task',
+            owner: 'bob',
+            status: 'pending',
+            blockedBy: ['task-a'],
+            reviewState: 'none',
+          } as TeamTaskWithKanban,
+        ],
+      }),
+      'my-team'
+    );
+
+    expect(findNode(graph, 'task:my-team:task-b')?.isBlocked).toBe(false);
+    expect(graph.edges).toContainEqual(
+      expect.objectContaining({
+        source: 'task:my-team:task-a',
+        target: 'task:my-team:task-b',
+        type: 'blocking',
+      })
+    );
+  });
+
   it('aggregates blocking edges through overflow stacks so hidden blockers stay visible', () => {
     const adapter = TeamGraphAdapter.create();
     const graph = adapter.adapt(