NOT too many authorizations!

I am a pro dj. I have three MacPros- each with 3 hard drives with different OSs (from Lion to Monterey). I keep 2 additional (virgin) hard drives with MY music library to keep Apple from effing my collection as it did twice before with Apple Match and Sync. I have my two travel laptops which I manually sync to my Master collection.

I just upgraded 6 hard drives to SSD drives but Apple Music won't let me play MY music, 95% of which I uploaded from CDs and the balance I BOUGHT on iTunes Store. If I boot from Catalina I am still using the same computer AND same music files if I am booting into Monterrey. Irregardless, if I don't authorize a particular OS, why won't Apple let me play ANY of MY music? How can I turn off iCloud syncing, it is no longer in the Music preferences?