x.v.colour is indeed off. And I cannot find any firmware anywhere. Have to check the version tomorrow. What else would cause the HDR menu to be hidden? The input is recognized as HDR10 and colorspace 2020.
I have included a couple of pictures
The input is set at 1080p. You need to input a 4K signal I would bet. Have you tried that?
Make sure your HDMI ports are set to Enhanced Format too.