highkiller If you're on a Quest 2 the highest resolution it can play is 8k (4000), so my guess is that it is just reverting to a resolution the headset can play.
That being said i just had a look at the scene you recorded and i don't have the option to choose 4320 and the highest i have is 4000 which plays fine.
You seem to have a glitch where 4320 is available - maybe this resolution is upcoming for Quest 3 ??.
There will be no noticeabe difference between 3880 or 4000 so i wouldn't worry about it especially as streaming has very mixed results anyway due to current issues with DeoVR.
