When I use the HDR settings with my Apple TV 4k the picture and audio break up. My Panasonic LED TV VIERA TH-50DX740U supports HDR. I have purchased the fastest/newest HDMi cables available. When I turn HDR on I definitely notice the Dynamic range is increased. Whites are far brighter and whiter and contrast is increased. However the picture and audio intermittently break up. As I have the Apple TV going through my receiver, I am wondering if the Receiver does not support HDR? The receiver is a Pioneer VSX-830-K. Could it be the receiver? Any other suggestions. I use wi-fi for the Apple TV. I am getting download speeds in excess of 200 Mbps at the Apple TV and over 400 Mbps at my computer hardwired with the CAT6 cable, so I believe my internet speed is not the problem. Apple say that you only need 25 Mbps.