Indeed, cover art is the usual suspect here. There is an open issue PICARD-1001 about cover art and the changed status of releases. But this is a tricky issue and I wouldn’t be surprised if there is more than one root cause for this. But I haven’t looked into this myself in detail, yet.
Could you share some information on your setup? The following would be helpful to reproduce this issue locally:
- Your exact settings in Options > Cover art and subsections there (a screenshot of the cover art related option pages and dialogs “Cover Art”, “Cover Art Archive”, “Cover Art Archive” > “Select types” dialog and “Local Files” would be great)
- The file format of the files being saved
- Is “Clear existing tags” set or not?
- The exact release, but that I already found: https://musicbrainz.org/release/36c0baa0-b16e-490d-86e5-6167d63ba8e9/