5k2k ultrawide (lg 34wk95u) cannot get hdr to work

[Wicpar]

Hi i recently purchased the LG 34wk95u, and made it work in its 5k2k glory on my thinkpad p1 (quadro p2000 maxQ) through a thunderbolt 3 connection. But one thing is missing: hdr.

 

So i look into the settings, and find that it was set on displayport 1.2. so i change the display setting (in the physical display's menu)  to 1.4.

 

But to my demise this happens (see photo): the screen is split at its two thirds and repeats a previous part of the creen, and still no hdr.

 

So i plugged it in with hdmi, stole the EDID, went back on thunderbolt, loaded the edid onto the screen, and hurray it works. But no. I just tricked windows into recognizing the features, but it is unable to activate them... But the creensplit doesn't happen anymore!

 

The thinkpad has a 15EB controller which is titan ridge and should support thunderbolt 1.4...

 

So if anyone has an idea as how to fix that and finally let me watch useless hdr demo videos in their full glory please share!