The H3 is doing some sort of system reset, because my Joeys lose connection, I have not run downstairs to see what the main box is doing, I assumed since it's happening at the same time, that it is some sort of scheduled reset that doesn't warn the Joeys. I am not on the TV directly connected to the H3 when this happens, as I've said, it is only happening, with no warning, when I'm watching on my joeys.
So what could conceivably be happening is that the H3 goes into standby because the activity on the Joeys is not considered "activity", and since it's in standby it does it's maintenance reset and has no mechanism to warn viewers on the joey extenders that it's about to reset.