iTunes/Music App on Mac stuck on Getting Playlist Window - Tahoe

I'm posting this just in case anyone has had or will experience this problem. Took me weeks to solve.

So once I upgraded to Tahoe, I was having a problem with itunes/Music app. Whenever I opened it up, it would get stuck with a window saying "Getting Playlist". I had to click cancel 6 times before it would go away. But whenever I clicked a song in the Songs category list, the message window would appear again "Getting Playlist" and I'd have to click cancel several times before it played. This happened for every song I clicked on.

Songs in my actual playlists would play OK and I could use Command + right arrow to skip to next song.

One thing: If I turned off my wifi and stared iTunes, it opened fine and would play the songs normally. Still wasn't sure what iTunes was trying to get when the internet was on.

After going through all settings and lists, I discovered that over half of my songs I bought on iTunes were not on my computer by going to Account > Purchased. I think this may have happened when I upgraded computers.It was hundreds of songs.

Anyway, I downloaded all the missing songs, closed iTunes and then opened it up again. Everything worked fine again and problem solved. I'm guessing when iTunes opened, it had to gather the list of songs which included the missing ones against the server. "Getting Playlist" was probably getting stuck looking for the missing songs and maybe some of those songs were within my playlists.