Apple TV goes black screen at "up next" (when it's almost time to start a new episode in a series)

My Apple TV 4k is getting intermittent black screen again. This time it's when we watch a series (tried on iTunes and Disney Now). When the resolution switches for "up next", and it puts the ending of the current episode in a small screen, with the new one on a countdown... the screen goes black for a 2-3 seconds while the programming is still playing.

How can I fix this?

Also, how can I stop it from doing that annoying auto-minimize of what I'm watching? Might help solve the problem...