I don't suspect two mainstream apps got funky in the same way, and don't think that reinstalling them will help in this case.
There's something odd going on with your TV and/or 'home theater' sound system. I suspect that the 'weird noise' is happening whenever something is being played, but it's most noticeable while paused.
Please tell us about your system and how it's connected - TV model, any soundbar or AV receiver, etc. Also, what does the ATV4K report under Settings > Video and Audio [under AUDIO] > Audio Format (should report Auto: [something]).
A quick search reports an issue like this when the ATV believes it's playing through a Dolby 5.1 surround system, but the TV and/or soundbar are merely capable of stereo. You would fix this problem by changing the Audio Format setting referenced above.