Amrit described this in the other thread you posted in: Ubuntu 21.10 - "Failed to grab modeset ownership" with 495.44 - #37 by amrits
The issue here is that any application opening one of the /dev/dri/card* device files automatically attempts to get DRI “master” permission. In the NVIDIA driver model, that tries to get “modeset ownership” on the corresponding GPU. If another driver component already has modeset ownership, then getting “master” fails and prints this message.
This happens even if the application doesn’t want or need DRI master.