Yamaha RX-A3040, AppleTV 4K and Dolby Atmos

I have a Yamaha RX-A3040 audio receiver with firmware v1.98 and an AppleTV 4K OS 15.6. When I select Dolby Atmos on in the audio settings, I do not get the Yamaha RX to decode the audio. It does say PCM but I cannot hear audio. When I select Dolby Atmos off in the settings, it shows PCM and it does decode audio as 5.1 and 7.1 through Yamaha. Any suggestions? I am so frustrated with all this. I even changed all my HDMI cables to high speed cables.

Sincerely, Lenny