I had to use this when I didn't follow directions on my XCP-NG lab system.
Also a note to Freenas/Truenas users, make sure you "keep" a few old versions when you are upgrading things on your NAS, for exactly the same reasons. Yup, had to roll back on one of my production NAS this summer, nearly had a heart attack when stuff booted back up and none of the shares were accessible.
The only GPU I've tried to pass through has been an old Quadro 2000 card, and it seemed to work fine (though the old driver is a bit difficult on Win Server 2022). But the host also has a cheapo server GPU for XCP-NG to use for boot.
I mention Quadro because those didn't have the crippled firmware blocking them from pass through like the Geforce cards have/had. Kind of a dirty trick from nVidia!
Sorry I don't have any newer cards that I can test with, and I also only have Quadro cards here at all, "required" for some of our software.
What I did find out is that if you pass through a GPU, you can not migrate that VM to another host, even if that other host has the same model GPU installed. And with that my GPU pass though testing is complete.
@janvanhumbeek how long did you run Memtest for? Can you run it for the same length of time to see if it locks up. Check for BIOS updates. From the Logs you have C States errors so looks like Power management is not working you may need a different Kernel.