After migrating Music.app library, no playlists or ratings or date added - but the SONGS are present?

I'm attemping to migrate from a Mac Pro to a new M1 laptop. My library is in good condition with some 16,000 non-DRM tracks, ratings and various static and smart play lists.

When I copy ~/Music/Music/ from the desktop the the lap top, everything copies over fine, including the file ~/Music/Music/Music Library.musiclibrary and everything under ~/Music/Music/Media.

SOO.. I should light up Music.app and see an exact duplicate of my desktop, right?

Not so. There is no data about the tracks at all. Items I depend on regularly are simply not present.

No playlists.

No ratings.

No "date added", or rather, there is data, but it's the same date for all 16,000 tracks, which makes sorting for new music impossible.

I have attempted using "OPTION start", ie; holding the option key at Music.app launch, then selecting the library file in question, but get the same results.

What could I be doing wrong? Everything on the the generic internet points to iTunes.app vs. Music.app, but they all assure this is generic operation that should be easy, just copy it all and you're done..

What could be going wrong? I am NOT ready to abandon two decades of song ratings and play lists!!

Thanks so much!!