Hi, I had the exact same problem and I've been debugging this for a while.
What I've done is the following:
- Create a project using GLES3
- Revert settings to use GLES2
Observed:
- No problems on Android Emulator or Windows
- Screen flickering all the time on OnePlus6+
I did the actions in:
https://godotengine.org/qa/7172/godot-logo-blinks-continuously-dosent-loads-android-phone?show=717
And out of nowhere it worked. I did a process of elimination to pinpoint exactly what the might be by diffing the projects and re-adding settings.
In the end I saw that the setting: 'run/lowprocessormode' in the file: 'godot.project' was set to 'true'. Removing this line (set to false by default) resolved my issue for the screen flickering on Android.
I hope this helps for anyone encountering the same issue. Just started with Godot and I really enjoy it :).