Interesting... something like this....
https://www.reddit.com/r/oculus/comments/k36ja5/virtual_desktop_lateral_juddering/
It must be something only affecting some headsets. Have you tried a Factory Reset? I did have some issues on mine, but a factory reset sorted them out.
My Virtual desktop settings are.
Sliced Encoding on
VR Bitrate 98
VR graphics High
FPS 90.
In the Streamer
Automatic bitrate - off
Codec H.264