Problem syncing music after new iphone 12 Pro Max issue.

I just purchased the iPhone 12 Pro Max. I had the 10XS Max. Upon opening the box and getting it turned on both phones recognized each other and the transfer of data began. Everything seemingly went OK.

Then I went to plug my phone into the computer so it could create a back up. It took awhile but then I found an error pop up. See below. When I transferred the data from the old phone everything transferred OK. I can see and play all the music on the phone itself. Problem is, iTunes does not see all the music presently on my phone so it thinks that there isn't enough room on the phone when I go to sync my selected music. This also goes for any ringtones and audio books.

I realize that I could probably just delete the music app and all it's data and just re-add it, but considering I have over 12K songs on my phone I'd rather not take this route and fix the sync problem instead.

Any help would be greatly appreciated. Thank you in advance for the answer.