Apple TV temporarily blacks out on TV, yet feed/content continues

I have a Samsung UN65JU639DF television. It is NOT 4k, however we received an Apple TV 4k device as a gift. The screen randomly goes black (timing/duration is not predictable), and while blacked-out, we know the feed continues as when the screen comes back, the video has advanced during the blackness.

We have:

1. Confirmed up-to-date firmware on the TV.
2. Cold-booted it even though we had confirmed the software was up-to-date.
3. Provided a 4k high-speed HDMI cable (had presumed old-school HDMI cable might have been the cause).

Out of ideas on how to correct.