No sound streaming bug

If you're getting no sound while streaming, especially with the built in mixer streaming, most likely what Microsoft already told you is true.

The same issue occurs with The Division 2 and has been acknowledged by that developer to be a bug.

It's not something Microsoft can fix, especially if streaming other games has sound.

The best way to reach Live Support would be here:
https://support.xbox.com/contact-us

Step 1 ----Select Xbox One

Step 2 ----Select See other options

Step 3 ----Select topic (Ex. System Update)

Step 4 ----Select "Show contact options"

Step 5 ----Select request a call from support

I've had issues like this with some xbox applications to my solution was I have several sound options and I have just switched it to the other one and sound worked fine

Press and hold power button for 10 senconds, wait 2-5 minutes and turn your device again, check if it works

Does this happen with other Windows Store apps that you are aware of?

I would also recommend the Audio Troubleshooter by opening Start > Settings > Update & security > Troubleshoot > Playing Audio

Select it

Click Run the Troubleshooter

When complete, restart your computer then check if the apps are working.

You can also check on computer audio by right click the Sound icon in the Notification areas, click Open Volume Mixer

Is the Applications System Sounds slider up?

Check and let us know.

Let us know if the troubleshooter or other steps resolve this issue for you, if not we can try some other troubleshooting steps.