If the issue is more prominent when the cursor is showing, it could be the hardware cursor (default on KDE) causing the issue. When you use hardware cursors, the cursor is rendered on a different ‘plane’ on top of the rest, possibly causing desync. You could try disabling it with a environment variable (I think it was KWIN_FORCE_SW_CURSOR=1), forcing to software render the cursor.

550+ has Explicit Sync, which indeed causes a variety of issues still. Newer versions does bring things like multi monitor VRR, increased performance in VR and Wayland hardware cursors (and probably more).

DX12 support is usually handled through VKD3D, which has an open issue on the latest Nvidia driver. The ticket suggests you have to run at least Kernel version 6.9.3.

Rolling back the driver version would probably be through downgrade together with nvidia-utils and lib32-nvidia-utils, you can chain them in one command to satisfy the dependency resolver. e.g. sudo downgrade nvidia nvidia-utils lib32-nvidia-utils. Make sure to check if you run nvidia or nvidia-dkms.

All Linux iso’s, right?