So this is a recent enough regression, cannot say if it was added with beta 1.42.2.10102 but I suspect most likely it is.
I have local assets for all my artwork, so fanart.jpg for my tv show backgrounds. This is still working fine at the show level but is no longer working at the season level. See example below:
… you can see the fanart background image has changed to the plex supplied background and not my local asset version.
Workaround:
As a workaround I can copy fanart.jpg to season01-fanart.jpg and this fixes the problem.
I suspect the issue is that plex does not find a season01-fanart.jpg, its now defaulting back to plex cloud supplied artwork and not the show level user defined local asset of fanart.jpg.
Cool, its probably a symptom of the same issue. I seen a post a while ago saying the plex team are refactoring some of the scanner/agent code so that work could be a factor.
Thanks @Tion1, didn’t see the post from @Insomnic_1 which looks like the same issue (I only lurk occasionally these days on this forum for the sake of my own sanity)