Good Morning -
bk - I swear to goodness, BigSur is a MESS. It messed up my Apple Music and my iCloud drive does not function correctly. Since it's on a computer that I don't really use too much (because of this actually) I haven't really tried to suss out the issues. I did make a change from Apple Music to Spotify because my Apple Music library was all messed up because of BigSur. Luckily, all my music is backed up on two hard drives, but the fact that none of my music was showing up in Apple Music, I just got tired of the entire thing and let it go for a while. I think it may have to do with the amount of memory I have and the amount of memory it takes to run BigSur. I wish you luck!!!