Why isn’t Atmos working on AppleTV, HBO, and other streaming apps?

I have the same problem. Used to get Atmos just fine from Netflix, and since last month it doesn't work.

The show menus say Atmos but my receiver is only getting a Dolby Surround signal. Atmos still works on my TV Netflix app.

Also not getting Atmos from the AppleTV app on the Series X.

Disney+Atmos still works

Lack of testing, there is no apparent AV team internally at Xbox which is why it's approach is so messy and uneven. This why other boxes like Nvidia Shield or AppleTV outperform it.

The digital media player of Xbox is nothing more than Windows Media Player so very basic in operation.

Atmos is known to be buggy on Xbox due to the way MS have to inject system audio like UI sounds into the Atmos stream, they have a very complex audio upmix system which tries to make it work but doesn't always.

That's interesting. I also remember seeing that post that said the Atmos thing was only cosmetic. On the other hand, my AppleTV app on the Xbox is only outputting Dolby Digital 5.1 (not Surround) when the show menu says Atmos so I've just been assuming there is a bigger Atmos problem on the Xbox.

I'm having this issue too! All my other streaming apps are working except for HBO Go. How do I solve this?

Third party apps such as HBO GO are the responsibility of that third party. So it is up to HBO to make an app for xbox one. As far as streaming goes skydrive is available to stream movies