Music app on Mac only shows cover art playing the 1st song of each album

Yes, that's what is happening to me.

I have a brand new Macbook Pro M4 with Sequoia and I'm having lots of problems with embedded artwork of my ALACs and MP3s. I have all my albums with embedded covers, and when looking at the files in a Finder window (list, column and icon view) all thumbnails appear correctly.

But when I see those albums in Music app (it happens with my large external drive library but ALSO creating a brand new library and importing some of these albums) I can only view the artwork thumbnail right at the top of the Music player when I'm playing the 1st song of each album.

If I'm playing a #1 song I can see the thumbnail on the banner with the song, artist and album name. Even if I click to see the larger version, the artwork is displayed beautifully. As soon as I start playing another #1 song of another album, the artwork thumbnail changes inmediatlly. Everything works as expected if I only play the 1st song of each album. But if I change to a song that's not the 1st song of an album, the artwork thumbnail don't change and the previous song's artwork is displayed. If I click on the thumbnail to see the larger version, it appears completely black.

I tried rebuilding the artwork cache by deleting all the JPGs in the

"user/Library/Containers/com.apple.AMPArtworkAgent/Data/Documents/artwork"

folder but this doesn't help with my problem.

Please, any idea what's happening?

When I used iTunes in Monterrey (via Retroactive) all things artwork-related worked beautifully.

Many, many thanks.