Arris XG1v3 Contour 2 DVR video flickers only when playing On Demand content

Upgraded to the new Contour 2 Arris XG1v3 6 tuner DVR last week. I can see live channels perfectly and can record and playback my recordings perfectly as well. However, when playing any On Demand content (from any channel or any program on demand) thru the same dvr, the video has a slight stutter or flicker (maybe dropping a frame) every ten seconds or so. It's very distracting and takes away from the enjoyment of the program being watched. I swapped out the dvr twice with the same model Arris dvr and the problem persists.

Last week, all my levels were checked out by a Cox technician and were reported as being clean and strong. All fittings were replaced inside and outside the home, including at the sidewalk. The entire cable from the sidewalk to my home was replaced. My Cox cable internet modem is working perfectly as well as my home phone.

Can anyone offer some ideas or thoughts as to what could be happening? Cox Comm has run out of answers. Thanks in advance.