trying to open a file via right click in finder. Then, most of the times, but not always, system gets unusable because it messes with the screen – and I've got the feeling inoput via mouse / trackpad / keyboard isn't working but that's hard to tell because it is like flying blind.
IMac 24", M1, 16GB, macOS Montery 12.1 Beta (21C5039b)
Affinity Photo 1.10.4 A(AppStore version)
And it looks like this. First one is with open file in Affinity trying to place another file from Finder window (that's the 3 rows a 4 files on the right)
and this is when Mac goes to sleep while Affinity is running: