Just installed my Roku Element TV (55 inch) and tried to watch Direct TV through my Direct TV box - connected with HDMI cord - and the picture keeps freezing regardless of what channel the Direct TV is on....how can I resolve this issue? It is connected to the smaller Direct TV box in my bedroom. Should I purchase a new HDMI cord? It was working just fine with my smaller TV before I switched it out. - thanks for any help/suggestions you can give.