Alber Stelar replied at 2019-12-03 20:31:58
This only happens with MIUI style notifications

Hi there!

This issue is already reported by many users on various devices. Apparently it doesn't happen with all apps though. The bug is notified already, but I would still suggest you to send a bug report through the Feedback app in case no reports have been made from Mi MIX 3. Hopefully future updates would fix this issue.

Cheers! :-)