Bug Unity Android screen stuttering / flickering when using native UI (with video)

Hello, everyone! I recently faced the problem and I really need your help. The game starts to lag terribly on my android phone when I start using the native UI (e.g. navigation bar, notification panel or changing the volume level).

The game itself does not lag, everything goes perfectly under 30 fps, but when I start using the native UI, the screen starts to crumble (but still under 30 fps, without drawdowns). I recorded a video from another phone, because when I use a screen recorder, this bug disappears (probably the screen recorder optimizes frames somehow).

VIDEO:

Possible solution with Optimized Frame Pacing? No! Unfortunately, I cannot use this feature due to a critical bug on another phone (the old low-end phone starts to lag terribly and slow down after a couple of minutes of gameplay). Unity still can't fix it and I'm preparing a huge detailed bug report on this topic.

I have also tried setting different Application.targetFrameRate values, but the problem still persists.

I will be very grateful if you help me or tell in which direction to do my research.

 

Anyone?

 

what's your Unity engine version? I also have this problem when run our game on Android emulators on Windows PC.
I'm using Unity 2021.3.15f1