Dolby Vision for UHD Movies

Without knowing the BluRays your trying to watch there isnt much we can do.

I do know that not all UHD BluRays support Dolby Vision, they all support HDR10 (as its a free to use license) but Dolby Vision costs the movie studios to use. it.

Perhaps look at the back of the UHD box and see if it mentions Dolby Vision, if not its probably only using HDR10.

I have the exact same problem. Everything is supported except for Dolby Vision on my 4K-screen, but only HD-movies are playing, not UHD?

I don't see how an individual player has to be licensed. That's like saying every brand and variation of a BluRay player that supports it has to be licensed... the media is where the licensing should fall in long with the responsible production studio.
Games are supported in Dolby Vision on the X. I'm not sure if it's a hardware or a software issue with the XBox One X, but I'm betting the drive cannot physically do it. It doesn't make any sense to have a machine as a home entertainment hub and not be fully
capable of supporting today's media formats.

I wouldn't hold your breath. Dolby Vision is a proprietary HDR format needing manufacturers and producers to pay licensing fees whereas HDR10 and HDR10+ are open standards. With Blu Ray sales dwindling in comparison to the movie market share being snapped
up by streaming giants, I can't see MS making the investment in getting the blu ray player app licensed.

I definitely think It would be good for xbox to have . 👍