I bought a Sony x900f 75" TV and hooked it up to my Marantz AV7704 via the x900f HDMI 3/ARC to the Monitor 1 ARC on the AV7704. Unfortunately I only get stereo when I send the signal from the TV to the Sound processor when viewing Netflix. I haven't tried too many other sources on the TV so I am not sure whether it is the TV in general or Netflix in particular causing the problem. I have been unable to find any settings either on the TV or the Sound processor. Where should I look, and what troubleshooting steps should I use to resolve this issue?