I just upgraded my 2020 iMac to Sonoma OS. Prior to this, I always got a solid 60 fps, give or take 1 or 2 frames. With the same game settings on Sonoma, I still get 60 fps +/- 1 or 2 fps. However, when dropping to 58 or 57 fps, it’s very exaggerated on screen. More like 10 fps. It still says 57 or 58 fps though. I tried everything in the settings and nothing helps.