Found it! In case anybody else runs into this issue, here's what it was:
I have a Gigabyte AB350 Gaming 3 motherboard. Unless you know just where to find it, you'll never see the virtualization enabler. It's here:
MIT -> Advanced Frequency Setting -> Advanced Core Setting -> SVM Enable.
For some reason, it was disabled by default.
Thank you very much for your help with ideas on where to look.
