Can't authorize a new system even though I deauthorized 2
I recently purchased a remanned iMac from 2015. I wanted to authorize it to download my Apple Music but it said I already had 5 authorized. One was a Mac Mini I no longer use and a PC linked to iCloud I rarely use. so I deauthorizeed them but I still can't authorize my Music. I went through all Community questions and no solutions worked for me.
iMac 27″, macOS 11.1