a guy have this same problem on his samsung device told me the problem showed up after an update...also there is another guy playing a game named diablo immortal on his s22 ultra posted about this issue ....i installed that game and screen recorded it just to check and there was no audio as well ... so can you please try and install one of this 2 games (world of tanks blitz - diablo immortal) and see if you will have any issue recording it