Cannot sync with iTunes since iOS 12.4

I have an iPhone 10Xs with firmware 12.4.1 (latest). I have Windows 10 recently updated to version 1903 with the itunes version 12.9.6.3

Since last week, I have not been able to sync with itunes (last successful sync was Aug 12). iTunes recognizes the phone and when pressing sync button, it verifies what tracks it needs to sync and immediately finishes. The new tracks that are supposed to sync are stuck in “queue” with a dotted circle to the left. I see this when viewing the music on the device…

I tried everything you can possibly imagine to resolve this problem. Tried a different factory-default phone, different windows 10 with same update release and earlier release, uninstall & re-install itunes, reset the library, updated all drivers, disabled iCloud music library on the phone and itunes... tried various suggestions found on internet. I’ve exhausted all options.

When the problem started I was using a slightly older version of Itunes and it was not working either, so I know the problem is not the latest version of itunes. I narowed it down to iOS 12.4

Anyone else has this problem? And is there a solution?