[DaveBlake]

Hm, maybe it was due to the DB migration from Krypton to Leia. Can't rule anything out since that DB has been through alot, including two migrations and manual sql adjustments
(manually rated ~ 25000 songs, so i'm not scanning in a new one, nu-uh).

@VelvetKevorkian I hope to add facility to export/import the dynamic song data e.g. last played, playcount and ratings in v19. I didn't get the time in v18, but I am aware it is a lack. Meanwhile if you are up for "manual sql adjustments" then I can suggest SQL needed to repopulate a newly scanned library with the song playback history data from a previous one.
 

For now i manually chose the correct local thumbs again for the artists without one, they weren't that many and i could not see a pattern why some were without one suddenly.

I understand why you would just fix manually, but I am interested to know why some local artist art was not picked up. Was the Wildhearts one of those artists, and do you have any other music involving them that isn't in folder under that folder? Or music by other artists in that folder? Don't worry that you can't see a pattern just dig into an example. I can also give you some SQL queries to explore what Kodi thinks about folder path uniqueness, or perhaps simpler just let me have your music db.