Hi @shabbir7252  , i think you could re clear the cache.

1. From your Android phone's settings, click Apps(varies by device).
2. Choose the QuickBooks app from the list.
3. Click Storage.
4. Choose Clear data

You can reinstall quickbooks app.

You should try refresh QBO app

Here's how:

1. From your iPhone's settings, click Apps(varies by device).
2. Choose the QuickBooks appfrom the list.
3. Go to Menu ☰.
4. Select Help & Feedback.
5. Look for Refresh Data.
6. Tap Refresh.

You should try too resetting data.

To do that:

1. Click Help on the navigation bar at the top.
2. Select Reset App Data.
3. Allow a moment for the process to complete, and then close the app.
4. Be sure to right-click the app and Run as Administrator when re-opening.

If still not progress, you could contact customer support team.

Here's how:

1. Click Help on the top menu.
2. Choose Contact us.
3. Enter mobile app is not syncing in theWhat can we help you with? field.
4. Click Let's talk.
5. Choose Start an email to connect with us.

Related articles : 

-  Clear cache 

- System requirement 

Comment back if needed. Good day.