HDR to SDR conversion is broken (v. 15.7.75 and .77 also)

As the title says, I'm having problems with HDR to SDR conversion not working (through MPC Video Renderer)
It only works on a fresh install (you finish installing K-Lite Standard and then open MPC to play a video file), but as soon as you restart your system HDR->SDR conversion breaks, not working anymore.

Everything running on 64 bit Windows 10 and i7 8550U CPU with Intel UHD 620 Integrated Graphics

During playback look at:
MPC-HC menu > Play > Filters

You should see LAV Video Decoder and MPC Video Renderer there. You should NOT see ffdshow or VSFilter/DirectVobSub. Those are not compatible with HDR.

These are the active filters:
https://i.servimg.com/u/f91/20/26/96/53/filter10.png

These are my LAV Video Decoder settings:
https://i.servimg.com/u/f91/20/26/96/53/lav_vi10.png

Example of how colors are displayed on both MPC and VLC (I only installed codecs for MPC)

MPC: https://imgur.com/a/cQKKf6z

VLC: https://imgur.com/a/NM9E8gd

Filter list looks good.

Press Ctrl+J to show statistics overlay of MPC Video Renderer. Make a screenshot of that. Compare that in working and broken situation. That might give us a clue what is different. It is strange that it works before restart.

Otherwise try with madVR as renderer.

Working HDR: https://i.servimg.com/u/f91/20/26/96/53/workin10.png

Broken HDR: https://i.servimg.com/u/f91/20/26/96/53/broken10.png

madVR works fine by the way, I wanted to use MPC Renderer because I've seen it's less resource hungry

I think the working screenshot is wrong (same as the other one)? Here it looks like this for a HDR video:
https://imgur.com/a/qsQF38A

You could try the "Use Direct3D 11" option in MPCVR.

Ticking the "Use Direct3D 11" box actually solved the issue, thanks for your time.

By the way the file I'm playing is a BluRay remux of a notorious movie released last year, as far as I know recent movies all make use of HDR so I took it for granted that this one would too

Could you give me a link to that video? Torrent or nzb is fine. Then I can test it here, because it is weird that it worked initially with default settings.