Unlike all my previous cars, it can't see compilation folders, is erratic in its handling of properly tagged ripped commercial CDs, seems set up to favour streaming, yet gives specific support for an attached device which Apple stopped selling 5 years ago. Crazy.
I've spent hours on it. I'm done. I've re-ripped (in FLAC format) my old CDs in the paid for version of Media Monkey https://www.mediamonkey.com/, used it for artwork and tagging, double checked the album/track properties on my laptop, and still it splits some albums. Whether it's the malign influence of Gracenote, I don't know.
Two examples. Amy Winehouse Back to Black is split even tho the album and track properties show them as the same album. Best of Bowie is a 2 CD compilation album. All tagged to that album. It splits it into 4.
Only bright note. My own compilations now show in Playlists (don't snigger at my musical tastes). Used the free Mp3tag https://www.mp3tag.de/en/ for this, as the MM equivalent tool for playlists isn't intuitive for me. Saves it as MP3TAG.m3u within the album. Renaming to match my folder name produces the attached - even tho the program puts the original within the album folder, not to the root of the drive as has been suggested is essential.
Still, progress. The list of folders under the Playlists heading is the nearest I've got to what I had before. Indeed, any new CDs I buy I might create a playlist for it so it appears there. Much more convenient.
But for now, I'm done with it
