Mac mini, macOS 15.2
It would seem that the iTunes/Apple Music artwork fetching mechanism doesn't always work correctly. A Google image search should let you locate a suitable image that you can paste into the artwork area of the Song Info dialog.
tt2
Correct. Although it's worse than that. After spending years fastidiously collecting the album artworks, the app has removed hundreds of them. The album artwork udpate feature has not been working since around the time the monthly subscriptions were launched. May be able to write a script to automate the image search you suggest.
Have you checked to see if some of these albums have embedded artwork that isn't being displayed correctly in the app? Do you see artwork in the Song Info dialog, or in Finder?
tt2
Does your Album Artwork sync system in Music/iTunes work?
