what are you getting in 4K on sat?
as an aside, I have DL some 4K stuff, plays fine on my laptop using an additional codec, but sound and no picture on my box,
my box [ formuler F1 ] isnt AFAIAA capable of proper 4K , but it does play UHD on sat.
could the zgemma be similar in thats its like the old "HD ready" TVs ?