I spent hours manually sorting my library to my liking, and since the 19th of April, the order is completely random and changes every few seconds while viewing my games. Tried to restore a backup but the issue persists sadly
Same for me, it looks like the refresh keeps rearranging the sorting. It might be due to the web app being developed.

I have the same issue with the manual sorting of queued games. It happens on iOS, iPadOS and MacOS.