does xbox not have dolby atmos??

If the game does not support Dolby Atmos, then the audio is normal stereo. Microsoft are working on updating Dolby Atmos, where if the game does not support Dolby, the audio will be converted to simulate Dolby Atmos.

Does not seem to work for me. It says Dolby Atmos is selected. but no Dolby Atmos is displayed on receiver.

If you have a sound bar that supports Dolby Atmos, then it wont cost you anything to use it, only the headset portion of Dolby Atmos is $14.99. I use Dolby Atmos and it does sound great, but only for games that support it, otherwise it just sounds normal
for the games that don't.

I have dolby support - and dolby access. It works perfectly wirh netflix, atmos games, you tube etc, its purely thr UHD player ane or does not support dolby atmos. Needs an update from microsoft

Open the Guide by pressing the Xbox button.

Go to settings.

Then go to the Display & Audio settings.

Under the audio settings, check which audio format you use for your headphones.

If you set it to "Dolby Atmos", you need to have PURCHASED the Dolby Atmos for Headphones app. If you only got the free Dolby Atmos app, this will only give you 14 days of Dolby Atmos to test it out, and then stops working.

Try to change your audio format to Stereo or Windows Sonic (which is also a spatial 3D sound Format like Dolby Atmos).

Does that work now?