I was able to watch Netflix and Amazon Prime in UHD HDR on the 4K X1 DVR XG1v4 earlier last year on my Samsung 4k TV. I have not been able to watch these this year via the same X1 DVR. But via the same X1 DVR I can watch Youtube and other X1 native shows in 4K. The X1 video resolution is set for 2160p30 4k UHD. I have checked the Netflix subscription that is still set for the premium plan. I deregistered and re-registered both Netflix and Amazon Prime but that did not help. I rebooted the DVR, reseated the cables, but no luck. If I directly watch Netflix or Amazon Prime via the Samsung app, the 4k programs appear in 4K UHD HDR. I called Xfinity support but their Level support was unable to help. I will try the Xfinity level 2 support. If anyone has come across such an issue and found a resolution, please do help. Thank you!