I have the same issue, and I don't understand why ROKU finds it necessary to program the Ultra to automatically revert 'display type' back to 1080p Dolby Vision every time the power is shut off. I have the Ultra plugged into a Yamaha Aventage RX-A3080 that is also capable of 4K HDR Dolby Vision, as is my LG TV. Once 4K HDR is selected, and the "can you see this" screen appears, and you successfully change the screen resolution, it should STAY THERE, PERIOD. The Ultra should NOT be automatically changing the 'display type' back to 1080p. Nothing is more annoying, except for the new "ON NOW" at the top of my home page... that we CAN'T MOVE or DELETE. I know ROKU can FIX these things with a simple UPDATE, same way they ADDED them, and I really wish they would.
