From the video, this looks to me like there is a hardware problem. Some things to try:
- Try connected the NUC to a different input on the TV.
- Try using a different HDMI 2.0-compliant cable.
If one of these doesn't fix it, you may have had a failure in your DP-to-HDMI IC. In this case, the only resolution would be to have Intel replace the unit. To initiate this process, you need to directly contact Intel Customer Support. Here is contact information, sorted by geography:
You can also attempt to do this via the chat service (available here: Intel Customer Support Chat Service), but understand that this is English-only and is subject to the 9-5 hours in the Pacific Timezone.
Hope this helps,
I have downgrade to BIOS 0057 and flashes disapear. But HDR still doesn't work, in all driver versions (4877, 4901, ...)