After the latest update, Looking Glass does not exceed 67 fps, although it had about 120-130 before. The creator of Looking Glass, Gnif, says on his discord support page that this is not a Looking Glass issue. Timeshifting to the pre-update snapshot resolves the bug. It is difficult to impossible to find which package I should roll back when about 500 of them were updated in a single shot.
AUR packages should be rebuild even there is no update for them, once there was a major system update.
I see, sorry, there are some things I don’t know, I’m a relatively new user. But still, we couldn’t diagnose the issue on Looking Glass discord server, here.