Thanks, Camo! Could be. Saturday when this first happened I unplugged the HDMI cable, waited 5 seconds, & plugged back in without solving the issue. Reset did fix it. I know my cables are complaint. If no one else is experiencing an issue like this it has to have something to do with Dish. Either the outside dish is aimed wrong (doubtful) or the H3 is the problem (probable). I say probable because why would the recorded Planet Earth II, 4k not play at all? It had no sound, no picture until a reset of the H3.Sounds like a handshake issue with the HDMI input. I can recreate blank screen if while watching recording unplug HDMI from TV and go through non compliant HDMI switch (splitter). I lose the 4K and screen will go blank/black. To reset I need to reboot receiver but occasional it will come back if I just cycle power off/on.
I will investigate further!