Apple Music syncing issues after migration and manual import

Having an issue with Apple Music, syncing and have lost 3/4 of my music, playlists, etc. I am on a Mac Studio 2025, Sequoia 15.5. When I did the migration from the older Mac Studio, I did lose some songs, playlists, but managed to get most of those back over time doing various things. All of the music and playlists are still on my iPhone 15 Pro Max. Today I had a particular issue with a playlist, and grabbed those songs from the older computer onto a flash drive. I put those songs into a desktop folder temporarily. When trying to put those into my Apple Music desktop, things went wrong. Long story short I am getting an error message because I turned off "Sync" in Apple Music, then closed it down, then turned it back on again. Everything tried to sync but I started to get an error message, (The Cloud Music Library can't be updated right now. An unknown error occurred 4007). AI told me to do the whole Sync option and that's where the major problems are. I apparently now have two music library folders, and AI is trying to walk me through fixing this but I wanted additional input before everything goes South further. I'm assuming everything is in the cloud, and I do use Time Machine but don't know when the "dual music library" situation actually started and I would just be guessing if I try to restore from that. Sorry for the long winded post. Any help would be appreciated. Thanks. Doug