Home Sharing photos to Apple TV not working

I have an iMac with a large (1+TB) Photos library that I would like to access on my Apple TV 4K using Home Sharing and the Computers App. Unfortunately, I have not been able to get it to work. I have Home Sharing on with my Apple ID on the iMac and the Apple TV...when I open Computers and specify the library to use, I am able to see tabs and content in Movies, TV, Music and Home Videos...but Photos does not show up at all. This has worked for me in the past, but hasn't worked for maybe the last year or so.

I've tried all the combinations I can think of regarding rebooting everything, turning Home Sharing off and on, reducing the number of Photos albums shared, etc. At one point, the Computers app gave me the spinning wheel looking like it might be loading something, but eventually just gave me all the tabs except Photos.

Any ideas of how to get this to work? Home Sharing is really the only reason why I want the Apple TV unit, so getting this to work is a high priority.