Artwork on iPod Nano remixed with multiple album covers appearing in artwork / Apple Watch Album Artwork Sync Errors

I’m having some issues with album art synchronisation on my iPod Nano and Apple Watch SE 2. No issues with my iPhone or MacOS music app.

On the iPod the artwork is not only incorrect, it’s being remixed to include multiple album covers.

On the Apple Watch incorrect music artwork is being attached with playlist artwork being attached to songs and some music not syncing at all to Apple Watch.

Does anyone have a solution? Deleting and re-syncing doesn’t resolve the problem.