So here goes.
After October update for my 21ultra I seem to have an issue with apps exiting fullscreen kinda like the home button or back button is pressed but it does not display any touch activation onscreen, any video apps minimise to window and display the last opened app before my video app.
Full screen game apps attempt to minimise but stay open but not without a considerable stall in the game that's running in fullscreen, this happens every 5 minutes or so when in fullscreen and its ***** annoying having to maximise every few minutes.
I have looked on many links to no avail there isn't a lot on this issue, I have done a partition cache wipe but issue still persists.
Any suggestions anyone? Help would be apretiated before I loose all my marbles on this and have to resort to factory reset.
As you cleared the phones system cache files via the recovery menu I'd now suggest to put the phone into Safe Mode https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/ which stops downloaded apps and themes etc from working just to see if there's a clash happening.
Current Phone > Samsung Z Fold³ 5G.
Have you got this fixed yet? I am having the exact same issue. I have noticed about every 5 minutes the screen will blink once. If it is in full-screen at the time, it minimizes to the tiny box. Ughh
I had this issue with brand new S21 Ultra, returned it because I thought this was HW issue. It was fully updated.
Youtube in fullscreen (without Premium) exited fullscreen.
MS Teams call minimized into small windows as if I switched to different app.