Just read through the issues posted by ttnh. My receiver is a Yamaha CX-A5000 and I have a Genie C41-100. When I change channels I also lose sound. Like ttnh, this problem just started happening about 7 days ago.
I only get the sound back when I switch sources on the receiver from blue ray or Apple TV back to directv. Similar to ttnh, I tried new HDMI cables, I tried different ports on he receiver, but nothing worked as I always lose volume when I change channels. I hooked the genie directly to the TV and it worked fine, so thought process is it must be the Yamaha.
However, I hooked up an older, non-genie Directv box model number H25-100 to the same Yamaha receiver using the same cables. When I change channels, I never lose sound using the old directv box.
i did upgrade the firmeware on the Yamaha last night, but this did not resolve the matter.
Now I am back to my original thought, that the software on the Genie box must have been recently upgraded by Directv which has made it incompatible with the Yamaha receivers.
Looking for ideas to help resolve this issue.