No Shared Library option visible
I have set up a shared library. This is visible with all photos (58K+) on iPhones (2), iPads (2), Apple TV, all with the correct options. On my iMac (completely upto date running Monterey 12.6.4) there are only 96 photos visible, and the preferences pane does not have a shared library tab to use. I have repaired the library, restarted the Mac, tried everything but no luck. The "library" photos on the Mac has at the bottom that I need to update to the latest version of MacOS to see all photos. There are no updates left! Photos "about" reports "Version 7.0 (460.0.120)".
Any help please?
iMac 27″, macOS 10.13