Photos Library not available in Home Sharing or iPhone/iPad sync in iTunes

I have a strange problem - I'm migrating an old MacBook Air running El Capitan (10.11.6) to a new MacBook Pro running Mojave (10.14.6). I erased the drive of the MacBook Pro and installed Mojave from the recovery partition, and did a full restore of the old laptop to the new laptop from Time Machine using the Migration Assistant. Apart from the Photos Library not showing up in iTunes, everything else seems fine.

Here's the issue: from the syncing options in an attached iPhone and iPad, I can't select the Photos library, and I'm seeing the same thing with Home Sharing > Choose Photos to Share with Apple TV. "Photos" doesn't show up at all, I only see an option to select a folder (screenshot below).

I've followed the instructions in https://support.apple.com/en-us/HT204414 to designate the system library, but this hasn't helped.

I was able to get "iPhoto" to appear in the selection menu by following the instructions from https://discussions.apple.com/thread/6987566, but that didn't really help.

I also tried creating a new user on the new laptop, new iTunes library, and new Photos library. Plugged in the iPad and still wasn't able to select Photos - so the problem seems to be somewhere in the restored system software. Any ideas?