I have had my roku tv for almost 3 years now and suddenly the tv made no sound at all which I fixed by unplugging the whole tv and plugging it back in. Now my Xbox One has no sound on any HDMI port. Have tried a different HDMI cable as well as a different Xbox. The Xbox’s all work fine on a different tv.
So i have just had the same problem with my tv and i found a solution. First thing you should do is go into your xbox settings>Tv and display options> Video fidelity & overscan. Once your there press on hdmi, hit confirm then switch back to auto detect. After you've done that go to volume & audio output and find where it says hdmi audio. Press that and scroll to stereo uncompressed and boom it should now work.