A:Answer Dee,
First try a capable HDMI cable, some do not support 4k HDR. Second, your settings may not have HDR input enabled. Lastly, please try a different input. If none of this fixes the issue, please call us at: 1-888-935-8880. We are proud of our H8F and know HDR is a big part of what makes this TV great, so we want to make sure it works for you, 100%.