Cloud Music Library won't sync on reset Mac

I have had the same problem since June 20 with my 2019 iMac I9 27" which contains my main music library on an external ssd drive. My last known sync was the day before. Just bought a new iPad Pro M4 Friday, and it would not sync either. I reformatted my MacBook Pro M1 on Friday night also and it will not sync with Apple Music. My iPhone is still syncing and believing it or not my 2018 MacBook Pro still syncs. The 2018 model though is hardly ever used and I should state I have not checked it today. I contacted Apple Support Saturday. I spent over three hours with them working on the machines and taking logs for them. They are supposed to contact me tomorrow. Sunday morning the new iPad Pro started slowly adding a few items from my library. It still has not completed updating my library as of today. It normally times out after about 6 minutes. I sure hope someone comes up with a solution.

All of my Macs have started back syncing. I had a followup call with Apple support yesterday and was told that they were working on the issue. Several hours after the phone call my Macs started to sync.

After a Phone call with apple support, where I proved I had reformatted the Mac and started from scratch, and they took screenshots, they fixed it later that evening.

If I restored just my local database from TimeMachine, I could access my online tracks, but not sync or upload. Which makes me think that the online database is corrupted somehow when this error occurs, and they just need to reset it somehow.

Same with me since Saturday 15th, although syncing has been dodgy for a week. I turned sync off and on again and have lost access on Mac. My iPad has lost access now after switching sync on and off, but iPhone still working. iTunes for Windows also cannot access. If I replace the database with a backup from Time Machine, I can access previously synced files, but cannot sync further. Currently trying to speak to someone from Apple Support.

I'm also experiencing this

I've re-authorized and was still getting the same message

Signed out and back into account and same thing... but now it won't even show me anything I've added to library since June 24, 2024 on my Mac ☹️

Same problem here and no one at Apple seems to know how to fix it. Been going on since 6/19/24. I've spent probably 5 hours taking to various people who have no clue how to fix this.

my bad... it's only showing items I have imported... it is not showing items purchased or added from Apple Music

Everything shows fine on iPhone or even web player... just not the mac app