Concerns:
Preferences -> Layout (1) -> general -> artist pictures: [_] crop to a circle
Problem:
If you toggle the value and save the preferences, the change is not taken into account.
When re-opening the Preferences window, the tick box still has its previous state (before the change).
The only way to change the parameter is to edit MusicBee3Settings.ini:
<GUI_ArtistPicCircle>true</GUI_ArtistPicCircle>
or
<GUI_ArtistPicCircle>false</GUI_ArtistPicCircle>
Versions where the bug shows up:
MB v3.5.8242 P and above
Latest version without the bug:
MB v3.5.8237 P