DisplayPort card not working in Windows

I’ve got a DisplayPort card on a 12th gen device that seems to have stopped working, kind of.
Windows 10 and 11 are unable to detect the monitor plugged into it anymore (though it worked fine for a few days). The monitor does work when plugged into a dock, so the monitor works, and display output in general works. I’ve tried swapping the DisplayPort card to a different expansion port, and also tried the 12th gen 3.06 beta BIOS, but neither of those made a difference, unfortunately. The monitor doesn’t show up in the device manager either, so Windows appears to have no idea it exists.

I did test the card on my 11th gen board running Linux, and bizarrely, the card works there, so I have absolutely no idea what’s going on.

Unfortunately there are some DP expansion card units which are defect, I would open a support request.

Roger that. Thanks.