Sound disappears and H/P INPUT ON APPERS on the digital readout. The sound is off for 5 seconds to minutes. When sound comes back on H/P INPUT OFF APPEARS. This issue happens at any time when going through the Home Theatre of my 6700H AVR. No rhyme or reason. It will toggle on and off sometimes for an hour. Days will pass before it happens again. Sony Bravia 4k TV and Denon AVR 6700H. HELP!