diff --git a/CHANGELOG.md b/CHANGELOG.md
index 81c1328f..282ce166 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Fixed
+
+🐛(frontend) fix broadcast store sync #1846
+
 ## [v4.5.0] - 2026-01-28
 
 ### Added 
diff --git a/src/frontend/apps/e2e/__tests__/app-impress/doc-header.spec.ts b/src/frontend/apps/e2e/__tests__/app-impress/doc-header.spec.ts
index 34f0b4c4..4652f590 100644
--- a/src/frontend/apps/e2e/__tests__/app-impress/doc-header.spec.ts
+++ b/src/frontend/apps/e2e/__tests__/app-impress/doc-header.spec.ts
@@ -7,7 +7,12 @@ import {
   mockedDocument,
   verifyDocName,
 } from './utils-common';
-import { mockedAccesses, mockedInvitations } from './utils-share';
+import {
+  connectOtherUserToDoc,
+  mockedAccesses,
+  mockedInvitations,
+  updateShareLink,
+} from './utils-share';
 import { createRootSubPage, getTreeRow } from './utils-sub-pages';
 
 test.beforeEach(async ({ page }) => {
@@ -52,13 +57,54 @@ test.describe('Doc Header', () => {
     ).toBeVisible();
   });
 
-  test('it updates the title doc', async ({ page, browserName }) => {
-    await createDoc(page, 'doc-update', browserName, 1);
-    const docTitle = page.getByRole('textbox', { name: 'Document title' });
-    await expect(docTitle).toBeVisible();
-    await docTitle.fill('Hello World');
-    await docTitle.blur();
+  test('it updates the title doc and check the broadcast', async ({
+    page,
+    browserName,
+  }) => {
+    const [docTitle] = await createDoc(
+      page,
+      'doc-title-update',
+      browserName,
+      1,
+    );
+    await page.getByRole('button', { name: 'Share' }).click();
+    await updateShareLink(page, 'Public', 'Editing');
+
+    const docUrl = page.url();
+
+    const { otherPage, cleanup } = await connectOtherUserToDoc({
+      docUrl,
+      browserName,
+      withoutSignIn: true,
+      docTitle,
+    });
+
+    // Wait for other page to sync
+    await page.waitForTimeout(1000);
+
+    await page.keyboard.press('Escape');
+    const elTitle = page.getByRole('textbox', { name: 'Document title' });
+    await expect(elTitle).toBeVisible();
+    await elTitle.fill('Hello World');
+    await elTitle.blur();
     await verifyDocName(page, 'Hello World');
+
+    // Wait for other page to sync
+    await page.waitForTimeout(1000);
+
+    // Check other user page
+    await verifyDocName(otherPage, 'Hello World');
+
+    const elTitleOther = otherPage.getByRole('textbox', {
+      name: 'Document title',
+    });
+    await elTitleOther.fill('Hello Other World');
+    await elTitleOther.blur();
+
+    // Check first user page
+    await verifyDocName(page, 'Hello Other World');
+
+    await cleanup();
   });
 
   test('it updates the title doc adding a leading emoji', async ({
diff --git a/src/frontend/apps/impress/src/features/docs/doc-management/hooks/useCollaboration.tsx b/src/frontend/apps/impress/src/features/docs/doc-management/hooks/useCollaboration.tsx
index 14f3b715..553c0bbf 100644
--- a/src/frontend/apps/impress/src/features/docs/doc-management/hooks/useCollaboration.tsx
+++ b/src/frontend/apps/impress/src/features/docs/doc-management/hooks/useCollaboration.tsx
@@ -8,7 +8,7 @@ import { Base64 } from '../types';
 
 export const useCollaboration = (room?: string, initialContent?: Base64) => {
   const collaborationUrl = useCollaborationUrl(room);
-  const { setBroadcastProvider } = useBroadcastStore();
+  const { setBroadcastProvider, cleanupBroadcast } = useBroadcastStore();
   const { provider, createProvider, destroyProvider } = useProviderStore();
 
   useEffect(() => {
@@ -33,8 +33,9 @@ export const useCollaboration = (room?: string, initialContent?: Base64) => {
   useEffect(() => {
     return () => {
       if (room) {
+        cleanupBroadcast();
         destroyProvider();
       }
     };
-  }, [destroyProvider, room]);
+  }, [destroyProvider, room, cleanupBroadcast]);
 };
diff --git a/src/frontend/apps/impress/src/stores/useBroadcastStore.tsx b/src/frontend/apps/impress/src/stores/useBroadcastStore.tsx
index 2406d42d..03fb1985 100644
--- a/src/frontend/apps/impress/src/stores/useBroadcastStore.tsx
+++ b/src/frontend/apps/impress/src/stores/useBroadcastStore.tsx
@@ -5,7 +5,9 @@ import { create } from 'zustand';
 interface BroadcastState {
   addTask: (taskLabel: string, action: () => void) => void;
   broadcast: (taskLabel: string) => void;
+  cleanupBroadcast: () => void;
   getBroadcastProvider: () => HocuspocusProvider | undefined;
+  handleProviderSync: () => void;
   provider?: HocuspocusProvider;
   setBroadcastProvider: (provider: HocuspocusProvider) => void;
   setTask: (
@@ -15,11 +17,12 @@ interface BroadcastState {
   ) => void;
   tasks: {
     [taskLabel: string]: {
-      task: Y.Array<string>;
+      action: () => void;
       observer: (
         event: Y.YArrayEvent<string>,
         transaction: Y.Transaction,
       ) => void;
+      task: Y.Array<string>;
     };
   };
 }
@@ -27,7 +30,22 @@ interface BroadcastState {
 export const useBroadcastStore = create<BroadcastState>((set, get) => ({
   provider: undefined,
   tasks: {},
-  setBroadcastProvider: (provider) => set({ provider }),
+  setBroadcastProvider: (provider) => {
+    // Clean up old provider listeners
+    const oldProvider = get().provider;
+    if (oldProvider) {
+      oldProvider.off('synced', get().handleProviderSync);
+    }
+
+    provider.on('synced', get().handleProviderSync);
+    set({ provider });
+  },
+  handleProviderSync: () => {
+    const tasks = get().tasks;
+    Object.entries(tasks).forEach(([taskLabel, { action }]) => {
+      get().addTask(taskLabel, action);
+    });
+  },
   getBroadcastProvider: () => {
     const provider = get().provider;
     if (!provider) {
@@ -43,20 +61,16 @@ export const useBroadcastStore = create<BroadcastState>((set, get) => ({
       return;
     }
 
-    const existingTask = get().tasks[taskLabel];
-    if (existingTask) {
-      existingTask.task.unobserve(existingTask.observer);
-      get().setTask(taskLabel, existingTask.task, action);
-      return;
-    }
-
     const task = provider.document.getArray<string>(taskLabel);
     get().setTask(taskLabel, task, action);
   },
   setTask: (taskLabel: string, task: Y.Array<string>, action: () => void) => {
     let isInitializing = true;
-    const observer = () => {
-      if (!isInitializing) {
+    const observer = (
+      _event: Y.YArrayEvent<string>,
+      transaction: Y.Transaction,
+    ) => {
+      if (!isInitializing && !transaction.local) {
         action();
       }
     };
@@ -73,16 +87,27 @@ export const useBroadcastStore = create<BroadcastState>((set, get) => ({
         [taskLabel]: {
           task,
           observer,
+          action,
         },
       },
     }));
   },
   broadcast: (taskLabel) => {
+    // Broadcast via Y.js provider (for users on the same document)
     const obTask = get().tasks?.[taskLabel];
-    if (!obTask || !obTask.task) {
-      console.warn(`Task ${taskLabel} is not defined`);
-      return;
+    if (obTask?.task) {
+      obTask.task.push([`broadcast: ${taskLabel}`]);
     }
-    obTask.task.push([`broadcast: ${taskLabel}`]);
+  },
+  cleanupBroadcast: () => {
+    const provider = get().provider;
+    if (provider) {
+      provider.off('synced', get().handleProviderSync);
+    }
+
+    // Unobserve all document-specific tasks
+    Object.values(get().tasks).forEach(({ task, observer }) => {
+      task.unobserve(observer);
+    });
   },
 }));