Unable to import photos from iPhone to iMac
I have an older iMac that is running Big Sur OS 11.7.10, which is the latest version of Mac OS that this iMac can run. I am now unable to import photos from my iPhone 13 (running iOS 26.1) to the Photos app on the iMac. It just hangs up on "preparing to import from iPhone 13".
My iPhone photos automatically upload to my iCloud Drive, but Photos on the iMac can no longer automatically download new photos/videos from the iCloud Drive either. It just stays stuck on "updating..." at the bottom of the Library page in Photos.
I'd very much like to have the iMac Photos Library be up to date with what's in my iCloud Drive, but it's like they can't talk to each other anymore. What's the fix?
iMac 27″, macOS 11.7