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.
macOS Mojave 10.14.6 (18G95)