This was my output from vainfo. Does it match yours?
libva info: VA-API version 1.10.0
libva error: vaGetDriverNameByIndex() failed with unknown libva error, driver_name = (null)
vaInitialize failed with error code -1 (unknown libva error),exit
I installed GNOME myself to try Wayland because I couldn’t get xfce to employ two-finger right-click, and my preferred environment, Cinnamon, doesn’t let you change the compositor, that I can see.
Hopefully the rest of the group has some ideas…?
ETA: I just upgraded to the latest backported kernel (6.0.0) and am still getting that output, for what it’s worth…