This was for clear logos specifically. Logo - unselect image does not stick and returns upon a metadata refresh 
should be fixed in the next Beta 1.43.1.
Clear logo are being treated differently because we allow for them to be unselected in the webUI and they have a built in fallback of the title. Posters, backgrounds, and square art would all behave the same. Where if they are DELETEd via API calls something else will be picked on a refresh. This is because these art assets should have something.
If you’re willing to use a script to fix this, one could be made to use the currently selected background art for the square art and then lock them.
