DTV may have pushed an update last night. It's the only thing I can think of. The audio dropouts happen rarely now. Maybe try to move your C61 back and see how it works. I am glad to know that DTV is aware of this problem. I certainly made them aware and they opened a case for me. Now they need to fix the 4K channel change issue. Switching from an HD channel to a 4K channel and back to HD channel causes my screen to go gray. I have to power cycle my C61 to get back to normal viewing. Major pain. Let us know how you make out if you move your C61 back.
LG 65 EF 9500,Yamaha 3050,Oppo 203
Directv C61 4K box, Apple TV, SONOS Connect
Triad Bronze Center, Triad Bronze LR-H Atmos, Elan inwall surrounds, Velodyne Subs,
Savant Remote, Harmony Ultimate Home remote
"It ain't 4K if it ain't shot in 4K"