Last night, we sat down to watch TV and the oddest thing was happening: the volume on our soundbar kept decreasing. It was as if someone was pressing Volume Down constantly. We normally just utilize the Apple TV remote so we checked to make sure the actual soundbar remote wasn't being pressed by anything - it wasn't. Well, via HDMI CEC, maybe the TV remote is being pressed - checked that too and nothing!
We proceeded to factory reset the soundbar - no dice. Thinking back, we tried to recall any new devices in our house that may be causing interference but couldn't think of any. An update for the TV was available so we decided to give that a shot also. The TV then booted into safe mode - the plot thickens!
To our great relief, Robert had identified the issue and resolved it. You can reboot your Apple TV remote by doing the following:
Press and hold the TV/Control Center button and the Volume Down button at the same time. Hold the buttons down for about 5 seconds, or until the status light on your Apple TV turns off and on again. Release the buttons.
Hope this helps someone! We were going absolutely crazy trying to figure out what was going on. All we wanted to do was watch The Great British Bake Off with audio!