I discovered an interesting situation with my Sony KD-43X85K television and 4100 STB.
I was watching the Boston Red Sox game this evening on channel 1494 (NESN 4K).
I turned off the TV and STB when heading to the kitchen for supper. After eating, I turned the STB & TV back on using the 4100's remote (as I normally do)
Instead of seeing the game in progress, I saw the following appear on the screen:

Interesting...my television is 4K.
I ran the 4K troubleshooting tool and closed it out as it didn't catch anything. Once it closed, the game appeared on the screen as expected.
Being the inquisitive type, I turned everything off, waited for about 15 minutes, and turned everything back on. Saw the same message.
I turned everything off, waited again, but this time, I turned on the TV first, waited about 15 seconds and then turned on the STB.
Voila'! The game came on right away.
So, based on my non-scientific testing, at least when connected to a Sony KD-xxX85K television and turning on to a 4K channel....turn the TV on first, wait 10 or so seconds and then turn on the STB.
We do have a Samsung 4K television in the house. If the opportunity arises, I will test that set and see what happens.