I'm using a 2018 12.9" iPad Pro running 14.3 (currently beta 2) and I found a weird bug when trying to view the Photo Library.
On a fresh launch in full screen, the Files browser is shown, but the "..." in the upper right to access the Photo Library isn't visible, just the new folder, view options, and select buttons are there. However, if you pull up another app in split screen, the "..." button appears. After this the button seems to stick, even if the other app is removed from the split screen. However, once Pixelmator Photo is quit, the button will be missing again upon a fresh launch.
Not sure which part of my setup might be triggering this (I realize it might just be a beta bug), but thought I'd bring it to the attention of the devs. At first I thought I was going crazy and there wasn't a way to access the Photo Library
Discuss Pixelmator Photo and photo editing on iPad.