a bit of added info on this thread:
Thank you!
There was a post on the subreddit by a user who was using 2.1.35 and can no longer use it. It seems that 2.1.29 is the limitation for now. This bug does not seem to occur in Qt5, so I think it will work safely up to 2.1.49. (since pyQt6 is from 2.1.50).
So I think the ideal limit is 2.1.49, but I added old Anki support to my version of zoom addon (Anki 2.1.35-) so I think this change is not essential.