My new 11 Pro won’t back up to This Computer in iTunes (Back Up Now, etc. are grayed out). If I select iCloud for Automatically Back Up, it backs up to the cloud. I’ve restarted both the phone and iMac Pro. I installed the update on the iMac so it could talk to the new phone. I have the phone connected with a cable. I clicked Apply. I clicked Sync multiple times. The phone is unlocked and sitting at the home screen. Nothing relevant I can find on the phone. Nothing pertinent on the web, or on this site.
This problem is due to iMazing playing tricks with iTunes and disabling its backup process. iMazing isn’t usable, and I uninstalled iMazing (again) a week or so ago. To resolve the issue, see this note in iMazing’s website.