Audio Problems & Certain channels have gray screens

We lose audio on a channel sometimes but if we go up or down one channel and come back to it the audio works again. 

Also, when navigating up or down around one channel in particular that I watch all the time (which now has the channel info appearing but the screen is gray and the audio doesn't work) the channels before and after it will gray out with no audio but will reappear when you go past it and back to it. 

What's with the "Press select to continue watching or channel may be temporarily unavailable" message?

Thanks!