I actually dont have my mac anymore 😟 Getting a new 13inch Macbook Pro shortly.
I think its attempting to sync music actually. It will sync photos, contacts, apps, install apps, uninstall apps, etc just fine. It will even perform backups just fine.
When I try to copy music over however it tries to and then I get the "unknown error 13019" issue. It will even copy movies and shows I bought on iTunes just fine, and I can see them in iTunes but not on the phone.
All my music shows up on the phone when its connected to iTunes, however when its disconnected, nothing shows up.
I also just noticed that my music on the phone went from 11.4 gigs to 7.37 although there appears to be the same exact amount of songs in the local Purchased folder as there is on the phone.
I had an issue once where my music became corrupt and I had to delete it all. Unfortunately now I can do that as I cant synch to copy everything back.
Its really annoying honestly