Logitech z906 learn remote IR not working

My Apple TV 4K is not able to learn the volume controls for my Logitech z906 surround sound system. It looks like it works on the system, saving each setting as I press the Logitech remote control, but nothing happens when I leave the menu or try to adjust the volume with the Apple Remote.

Bizarrely it worked once for about a week or so after the latest update came out then suddenly stopped working. It makes me wonder if the Logitech remote has some kind of unique signature for its IR or similar.

my Apple TV is up to date, running tvOS 16.0