I believe using the VMs with a UEFI BIOS may have been the issue or at least contributed to it. I don’t have much time to look into this at the moment, but can look again if you still have issues.
My GB bios is all “as supplied” other than allowing IOMMU which I guessed you must have done to get as far as you did?
Like wise, this is my first AMD system in a longwhile so things are a bit new to me too! If you want anything specific I am more than happy to look it up for you.
Good luck!