I have a legacy Xfinity/Comcast DVR, can't seem to get surround from HDMI to work. Surround sound works fine with my DVR connected directly to my receiver via optical audio, but not when it's connected indirectly to my receiver via my TV's optical audio output. My TV is configured to pass through surroundsound, and works fine with my Blu-Ray player and Roku, just not my DVR.