I have a new LG C9 OLED TV and a new Samsung HW-Q90R sound bar. I'm trying to run the cable box (Xfinity) and a Blu-Ray player through the sound bar and then up to the TV via HDMI ARC. The Blu-Ray player works fine, but for some reason when I switch to the input for the cable box it shows up as "No Input" on the TV. I've swapped out cables, changed HDMI ports, etc., and have spent hours chatting with Samsung, Comcast, and LG to no avail. Is there a fundamental incompatibility between Samsung and LG, do I have a bad sound bar, or am I just missing a setting?