I'm using the latest version on Windows Store
When I organised some albums, some of them lost their cover in MusicBee, but they were still in the file and still appeared in the editing window. After restarting MusicBee, they still didn't appear, so I have to save them again. After that I tried organising more albums but none of them lost their cover this time so I think this bug won't occur every time. I don't know if this could be fixed or not. I just think this bug needs to be reported.
A little update: I just organised ALL of my albums and none of them lost their cover, great!
My organiser settings and one of the albums which got organised and lost its cover