HI, i decided to upgrade my U9-H from the marshmallow to Nougat today but every time I've tried to connect it to my 4k tv I get no signal ive tried all 4 HDMI ports and different HDMI cables. If I downgrade back to marshmallow I get a signal again on the same 4k tv, strangely if I connect the minix to a 1080p tv while running android 7.1.1 I get a picture does anyone know how to fix this issue please