Playlists in music are not syncing right between computers

Very longtime Mac user. I have a 2019 iMac at home and I just added a 14" Macbook Pro. The Macbook seems to have introduced errors with my Music playlists. Some songs cannot be played from within a playlist (on the Macbook - iMac still plays them fine). Follow them out to their album page at Apple Music, and they play normally. Just not from the Music app playlist itself. Also, on the Macbook the library has many 'cannot find file' errors that, when canceled, resolve themselves. (Tedious and annoying to go through each track in my library.) The Music app doesn't sync right on the Macbook Pro. Today a fresh mystery: changes made to playlists with my phone show up just fine when I log in through a browser. (The Djay Pro app can see them, too) But the Music app on both the iMac and the Macbook Pro won't update to reflect them. I'd like to reinstall Music on the laptop but I know it's integrated with the OS. One of the reasons I got a laptop is to work on playlists for my radio show. It's kind of useless like this. Womp womp.