I have the same issue and know for sure it is the XBOX One. I know this because I also have a coax feed from the back of my cable box which goes to a bedroom. The XBOX picture freezes while the coax feed in the bedroom continues to play. In addition, when I bypass the XBOX One and run the HDMI from the cable box straight to the TV the picture has no issues.
Comcast w/ Motorola RGN200N HD DVR
You have a serious problem Microsoft...very weak!!!
And I was making fun of the PS4 issues?!