The fact that it works connected direct to the TV me makes me think it's not a Cox issue. When did the problem start and what changed around then? Have you tried Denon support or their forum? Also, how do you have the box/TV/Denon connected to each other and configured exactly?
I changed my tv. I am actually not sure when this issue actually started. Also I think t+there was a denon firmware update. I'll try denons support next. I have no device that sends sound over HDMI that the denon didn't detect and make sound.
The cable box HDMI goes to the denon HDMI port 1 cbl/sat. The denon then goes to my tv HDMI port 2 that supports arc/earc.
What model TV is it? You may need to experiment with audio options in your TV settings.
Found the issue. The setting for deep color 4k causes the audio not to be received from the cable box. Unfortunately because my bluray player is on that input I have no choice but to have the cable box on a different input and feed audio back through the ARC. It is an LG G4
