@WonderWoman1824 You still haven't answered the questions in post 27 regarding the remote.
Also, did you try 1080i as a test?
Have you tried a different input on the TV. On some TVs only certain inputs may accept 4k, or certain other signals. Try all inputs if possible.
I have the same issue. It is the very same model and the fix is also the same. Have to unplug the HDMI then plug back in to trigger the box.
To recent posters. Have you checked out the following post which may explain why you're having the problem.
For those who've seen this issue come up again recently, note that IgniteTV have recently implemented HDMI-CEC as discussed in the following thread: