Just like when originally introduced, IK tracked parts like the arm appear to not work even when 'IsAnimated' is enabled on the physbone. This doesn't appear to affect things that aren't IK tracked like ears from what I've seen, but it does affect the wings of my avatar and the same for the same avatar model my friend uses.
Edit 2: It does happen on quest.
Edit: Other IsAnimated physbones appear to have also been affected as well, but some animations do work while others don't.