Photos "Export" greyed out
In a previous discussion
photo library confusion - Apple Community
I was advised to use Export -> Unmodified Original in the Photos app to transfer the photos from my iPhone to my MacBook. This worked perfectly but is no longer available. The export function is greyed out.
I don't believe I'm doing anything different than before, perhaps I changed a setting somewhere? I thought there was something wrong with the images on the phone so I tried taking a new picture but the problem remains. I've tried selecting all photos, or just individuals with no change.
The iPhone is a 6s running iOS 15.3.1 and the MacBook is 2021 M1 running 12.2.1 with Photos v7.0
I'd appreciate any suggestions you may have. Thank you
MacBook Pro 16″, macOS 12.2