Crackling volume and green pixelation out of nowhere?

I used to use my chrome cast everyday nearly all day. It randomly started having volume problems, like it'll start a show on Netflix then it'll be really quiet and randomly super loud and it goes back and forth. It sounds like when you're playing music through headphones but you didn't plug the jack all the way in. The hdmi isn't broken or bent and this just started occurring randomly. No chance it could've been accidentally nudged because it's behind the tv in a hard to reach spot.

Anyone know why this happened? Has this been reported before?