Not much consolation, but I'm having pretty much the same experience running windows 11
My hardware:
Intel Arc A750 Limited Edition
Asus Strix x570-e gaming
AMD Ryzen 9 3900X
Kingston NV2 2TB (passthru)
Unraid Version: 6.12
I am booting unRaid with CSM in the bios. Because the NVMe is passthru, I've booted up the system directly to Windows (switching to UEFI) to make sure everything works fine. GPU-Z recognizes the card, sees that ReBAR is set, all looks good.
I've also tried virtually mapping the soundcard onto the same virtual slot with no luck. I think there may also be an Intel Bluetooth device that comes with the card so I've begun experimenting with passing that as well (Going back to @SpaceInvaderOne tutorial talking about Nvidia splitting soundcards causing problems)
Current test I'm running is a VM with Ubuntu 23.04. Hardinfo see an Intel i915 card but testing with something like blender not seeing the Xe-HPG or intel-compute-runtime
Dave