No UHD output - Decklink Mini Monitor 4K

Installed and updated everything from a Decklink Extreme 3D to a Decklink Mini Monitor 4K as I'm moving into proper UHD HDR grading.

Problem is that even if I change the Desktop video settings to 2160p, when I start Resolve and change everything there to UHD, it is locked at a 1080p output. Even though all my settings, everywhere, is set to 2160p 25fps, it just output a 1080p 25fps image (that's zoomed in on the 4K material).

What is going on here? And why don't any settings seem to change the output when I'm in Resolve? I have the studio version of Resolve 17, the Decklink Mini Monitor 4K installed and updated with everything up to date. I get an output image fine with good performance, but it's only 1080p, not UHD 25fps.

(If I select 2160p in Desktop video settings, then start Resolve and my 2160p project, it switches over to 1080p in the Desktop video settings when the project opens and outputs a video and can't be changed even if those settings are set to 2160p. Closing Resolve, it switches back)

Applications override the Desktop Video settings as you've noticed. The issue seems to be the settings in Resolve.

In Resolve, the Project Video Monitoring settings can be overridden by the Timeline Video Monitoring settings so make sure you change the right one if there are any custom timeline settings in the project (right click the timeline in the Media Pool and select Timelines > Timeline Settings).

What's the DeckLink connected to? Maybe the monitor doesn't provide the correct EDID information (if connected via HDMI). I don't know if that's a feature they use in the DeckLinks but they do in other recent converters to enable auto scaling.

Thanks, that did it for resolution.

However, I do not get HDR working. Settings in project are all HDR, the same in the timeline settings as well as "HDR over HDMI".

I get 4K HDR 60fps over the cable I use from other sources, so the hardware is supported. But there's no HDR coming through.