I have the exact same issue as described in this past post. For some reason the discussion was closed despite never being publicly resolved. In short, game audio becomes distorted but is still recognizable (like a weird filter) the moment I launch any game. I'm using earphones through a DAC over the USB-C connection.
I'd also like to add two more findings, that weren't mentioned in the old post: 1) Before the most recent system update to Android 12 I could temporarily fix this problem by simply switching to the overview menu and back to the game. Once I did that the game audio normalized for the session. 2) Only the game audio is affected, as when I played some songs through my music player while the game is open, the audio from the player sounded perfectly fine, whereas the game audio remained distorted. From this I would guess that the problem is software sided and somehow related to games. Is this something I can fix on my end by tweaking some settings or is this a deeper underlying issue in the system?