Apple TV 4K suddenly not displaying 4K as an option

Was this issue ever resolved? We are having the same problem. Apple TV 4K connected to a 4K tv, same setup and connections for years, working no problem. Now suddenly out of the blue, we are not getting 4K when viewing 4K content from Apple TV, and the video format options do not even offer 4K as an option. Nothing on the system has changed recently.