Picture flashing and blacking out, audio stays on - X1 digital box

We have on-going problems with the picture, jumping, flashing, or momentarily going black while the audio continues to play on our X1 HD digital box. This only happens when watching via apps like Prime or Max; or some of the extra channels like SyFy, NatGeo, or HGTV. Regular broadcast channels are fine it seems (NBC, ABC, CBS, etc).This only happens on the main TV in the house with an X1 box, our other televisions have only regular adaptors and no HD service or are smart TVs where we stream only particular channels, and do not have this problem. The X1 box is routed via an HDMI cable through our BOSE component system. We have sent full system refreshes; used the troubleshoot/chat; changed out the HDMI cable; checked the cable coming in to the house; nothing seems to remedy it. I've used the chat enough that they now say I have to have a technician out to the house, but it seems that if it is only the one Tv (Which is also a newer tv) it HAS to be an equipment problem, yet they have not suggested that. And sitting on the phone with someone is futile when they're in Pakistan reading a script. I'm about to just unhook the whole thing and just take it back to the Xfinity store. Any ideas? I think we need to try bypassing the component system to see if the the BOSE system is having problems. But beyond that, I'm at a loss.