Xbox One audio dropping down to stereo uncompressed automatically

Same thing here. I set it to 7.1 and it changes to stereo uncompressed by itself, but not all the time. Just power cycled the XB1 and it changed back to stereo. I reset it to 7.1, so hopefully it acts better from here on in. I think kellycraven might be
on to something with the order, because when I had the XB1 set to turn on my receiver, it always reset to stereo. Starting up the receiver first seems to keep my in 7.1 more often. Then need to fix this soon.

I've had xbox one users power cycling and that seems to be working.

Try power cycling the xbox and the receiver and turning them on one after the other, then in reverse order. I'm wondering if one way is good and the other is resetting causing a reset to the default 2 channel audio. Xbox should not allow setting to a mode
not supported so I'm guessing it thinks the 5.1/7.1 modes aren't available when it's booting up.

Hi GENER4L PURPOSE,

Thanks for your post! If there are any issues with the audio output format switching on its own, try performing a soft factory reset. A soft factory reset will reset the operating system on the console as an effort to stabilize the console. Here's how to
do so:
Xbox One Factory Reset. Be sure to keep your Microsoft Account information ready to sign back into your account and choose
"Reset and keep my games & apps" so you do not have to reinstall your content after the reset.

Let us know how this goes, thanks again!

Had this problem since day one launch. There doesn't seem to be a rhyme or reason. I personally think it has to do with the xbox's ability to communicate with some receivers properly. They won't patch this cause most techs have never even heard of the issue
and others only a couple times which is because no one is calling to report it or they tell the tech it's resolved after going through their steps only to find out it happens again. I have changes the hdmi cables. I have set the settings of my remote to power
xbox on last as well as first. It just doesn't make a difference. It's evident to be a software issue but it will never be resolved so get used to it.