Been having problems with the A-B-function lately. It kind of works, as it plays the assigned piece of video, but the A & B-"flags" both just pop up on top of each other at the very end of the timelinebar, not at the separate points selected. They are also not saved for the next time you open the video.
The favorites and custom playlists do not go to the next video after you are past page 1. If you go to page 3 for instance and press "next" it will start playing from page 1 of the list. This happened after the lists were reordered from newest to oldest.
I have also noticed that there are loading problems on random videos a lot more often than before. This has been going on for a month or two. Either I get the three loading-dots just spinning or the video opens up but without timestamps or no access to timeline-skipping. Earlier this happened on maybe one in twenty but now it's more like three out of ten.
I'm on a Quest 3 with the newest app and have reinstalled it several times.