Notification problems

[rwl2004ns]

Hello , I am new here and have since a month the Poco X3. Problem of it is that like somebody sends a message at Whatsapp I don't get a notification of it. When I open Whatsapp a message appears at the top . Also mail is only working by opening of the app. This problem seems to be only when I get in Mobile data mode . When I have Wifi the messages streams in . Tried everything with auto start and till restrict data usage. Also Battery saver is installed as no restrictions . Is there somebody who can help me?
Thank you by advance .

Best regards

 

[Roner]

I finally had to disable MIUI optimization to solve the notification problems

 

[rwl2004ns]

Thank you for the andere ,but the problem is already solved. On the internet was a topic to delete the Gmail account in accounts and enter IT again after delete. After that the problem was solved. Looks crazy but IT worked.