Hi
You want to check your BIOS / UEFI settings.
Something like Above 4G and maybe Resizebar on AMD Plattforms.
Maybe have a look at that forum thread:
Or search for ACS or ACL with PCIe Passthrough.
PCI Stubbing?
Might help if the GPU driver freezes the system.
Or just put the passed through devices in the block list.
Last post might help?
https://forum.level1techs.com/t/the-pcie-passthrough-bug-is-back/