Do these tracks also have a “folder.jpg” file in the album’s folder?

Hey, Buzz. Thanks for the idea. I just checked, and whilst I have run Doug’s “Save Artwork as Folder” and “”Restore Artwork from Folder” on my entire library, 3 of the tracks in that album had the wrong embedded artwork. I’ve run “Restore” again, and it’s all sorted.

Strange that this didn’t show up when I viewed the individual track data in Apple Music?

I’m not an Apple Music user. Does Apple Music store it’s artwork elsewhere?

It is stored inside the same folder as the music files

So, Apple Music could have different artwork than SONOS?

This could be a confusing mess because there could be two or more versions (embedded track by track variations) of artwork for the SONOS library.

Exactly!

Does anyone have a solution please?

I have the same issue and it drives me batty. I corrected the album artwork in Apple Music last year. It shows as fine in the Music App in iCloud, Mac OS, iOS, and iPadOS. Everywhere but Sonos despite keeping the app up to date. 

How does one add the artwork to the folder? Frustrating to have to do that given that I don’t connect to my own library but rather Apple Music/My Music.