A bit of weirdness i notice seeing I been watch "from" on demand, IF i pick the 4k version and select the play next episode before it end next episode will be 1080i version. if I let play back end it will might give me options to pick 4k or 1080i version. If i stop episode then list pops up with other episode and i pick next episode from there it only 1080i.
I am probably explain this badly but yah, pick 4k version and pick next episode it does not reliably keep playing 4k version it seem to go back to 1080i more time then not. I might not be able to see difference between with 1080i and 4k version do all compression being used but my tv know cause it will say 4k 60fps for 4k and 1080i 60fps for 1080i