I've had an issue similar to that before, but I can't recall if I had to swap out the HDMI cable (poor connection/internal break) or if it was when I had HDMI enabled on the PS4 and was trying to 'strip' it with a splitter device, and turning off HDMI in the PS4's system menu fixed it.
On a side note, you can also look up past issues with the AverMedia LiveGamer Extreme 2 to find other troubleshooting ideas if the above don't fix it; it's literally the same capture device, licensed and put into a Razer-branded case (they did the same thing with the original Ripsaw and AM LGX).