diff --git a/src/app/core-ui/navigate-to-task/navigate-to-task.service.spec.ts b/src/app/core-ui/navigate-to-task/navigate-to-task.service.spec.ts
new file mode 100644
index 0000000000..ecfb2f1c66
--- /dev/null
+++ b/src/app/core-ui/navigate-to-task/navigate-to-task.service.spec.ts
@@ -0,0 +1,111 @@
+import { TestBed } from '@angular/core/testing';
+import { Router } from '@angular/router';
+import { NavigateToTaskService } from './navigate-to-task.service';
+import { TaskService } from '../../features/tasks/task.service';
+import { ProjectService } from '../../features/project/project.service';
+import { SnackService } from '../../core/snack/snack.service';
+import { DateService } from '../../core/date/date.service';
+import { LayoutService } from '../layout/layout.service';
+import { Task } from '../../features/tasks/task.model';
+import { TODAY_TAG } from '../../features/tag/tag.const';
+import { of } from 'rxjs';
+
+const TODAY_STR = '2026-07-06';
+
+const createTask = (partial: Partial<Task>): Task =>
+  ({
+    id: 'task-1',
+    title: 'A task',
+    projectId: undefined,
+    parentId: undefined,
+    tagIds: [],
+    dueDay: undefined,
+    dueWithTime: undefined,
+    timeSpentOnDay: {},
+    created: Date.parse('2020-01-01'),
+    ...partial,
+  }) as unknown as Task;
+
+describe('NavigateToTaskService', () => {
+  let service: NavigateToTaskService;
+  let taskService: jasmine.SpyObj<TaskService>;
+  let router: jasmine.SpyObj<Router> & { url: string };
+  let layoutService: jasmine.SpyObj<LayoutService>;
+
+  beforeEach(() => {
+    taskService = jasmine.createSpyObj('TaskService', [
+      'getByIdFromEverywhere',
+      'getArchivedTasks',
+    ]);
+    const projectService = jasmine.createSpyObj('ProjectService', [], {
+      list$: of([]),
+    });
+    const snackService = jasmine.createSpyObj('SnackService', ['open']);
+    const dateService = jasmine.createSpyObj('DateService', ['isToday', 'todayStr']);
+    dateService.todayStr.and.returnValue(TODAY_STR);
+    dateService.isToday.and.returnValue(false);
+    layoutService = jasmine.createSpyObj('LayoutService', ['focusTaskInViewWhenReady']);
+
+    const routerSpy = jasmine.createSpyObj('Router', ['navigate']);
+    routerSpy.navigate.and.resolveTo(true);
+    routerSpy.url = '/search';
+    router = routerSpy;
+
+    TestBed.configureTestingModule({
+      providers: [
+        NavigateToTaskService,
+        { provide: TaskService, useValue: taskService },
+        { provide: ProjectService, useValue: projectService },
+        { provide: SnackService, useValue: snackService },
+        { provide: DateService, useValue: dateService },
+        { provide: LayoutService, useValue: layoutService },
+        { provide: Router, useValue: router },
+      ],
+    });
+    service = TestBed.inject(NavigateToTaskService);
+  });
+
+  it('navigates to the Today list for an overdue task with no project and no tags (#8780)', async () => {
+    // Overdue = dueDay in the past → shown only in the Today "Overdue" section.
+    taskService.getByIdFromEverywhere.and.resolveTo(
+      createTask({ id: 't1', dueDay: '2020-01-01', projectId: undefined, tagIds: [] }),
+    );
+
+    await service.navigate('t1');
+
+    expect(router.navigate).toHaveBeenCalledWith(
+      [`/tag/${TODAY_TAG.id}/tasks`],
+      jasmine.objectContaining({
+        queryParams: jasmine.objectContaining({ focusItem: 't1' }),
+      }),
+    );
+    // Must NOT be short-circuited into the "same context" focus-only path.
+    expect(layoutService.focusTaskInViewWhenReady).not.toHaveBeenCalled();
+  });
+
+  it('navigates to the project list for a project task', async () => {
+    taskService.getByIdFromEverywhere.and.resolveTo(
+      createTask({ id: 't2', projectId: 'p1', tagIds: [] }),
+    );
+
+    await service.navigate('t2');
+
+    expect(router.navigate).toHaveBeenCalledWith(
+      ['/project/p1/tasks'],
+      jasmine.anything(),
+    );
+  });
+
+  it('navigates to the tag list for a tagged task with no project', async () => {
+    taskService.getByIdFromEverywhere.and.resolveTo(
+      createTask({ id: 't3', projectId: undefined, tagIds: ['tag-a'] }),
+    );
+
+    await service.navigate('t3');
+
+    expect(router.navigate).toHaveBeenCalledWith(
+      ['/tag/tag-a/tasks'],
+      jasmine.anything(),
+    );
+  });
+});
diff --git a/src/app/core-ui/navigate-to-task/navigate-to-task.service.ts b/src/app/core-ui/navigate-to-task/navigate-to-task.service.ts
index 81ad3fefa6..ee1770d9ed 100644
--- a/src/app/core-ui/navigate-to-task/navigate-to-task.service.ts
+++ b/src/app/core-ui/navigate-to-task/navigate-to-task.service.ts
@@ -33,6 +33,11 @@ export class NavigateToTaskService {
         throw new Error(`Task with id ${taskId} not found`);
       }
       const location = await this._getLocation(task, isArchiveTask);
+      if (!location) {
+        // Never fall through with an empty location: `''.startsWith` would make
+        // the same-context check below always true and swallow the navigation.
+        throw new Error(`Could not resolve a location for task ${taskId}`);
+      }
       recordSearchNavDebug('navigateToTask:start', {
         taskId,
         isArchiveTask,
@@ -101,6 +106,12 @@ export class NavigateToTaskService {
       return `/project/${taskToCheck.projectId}/${tasksOrWorklog}`;
     } else if (taskToCheck.tagIds?.length > 0 && taskToCheck.tagIds[0]) {
       return `/tag/${taskToCheck.tagIds[0]}/${tasksOrWorklog}`;
+    } else if (!isArchiveTask) {
+      // A non-archived task with neither project nor tags only ever lives in the
+      // Today list — either due today (handled above) or overdue. Route there so
+      // navigation reveals it instead of resolving to '' and silently no-op'ing
+      // (an empty location makes `url.startsWith(location)` always true). (#8780)
+      return `/tag/${TODAY_TAG.id}/${tasksOrWorklog}`;
     } else {
       devError("Couldn't find task location");
       return '';