Well, I ran another package update (dnf -y distro-sync) and more packages updated. This
time, I managed to get one of the problematic Windows VMs imported using Other OS as the
OS type (still can't get it set to its proper OS until AFTER the VM import). I'm
testing another VM, a much larger VM, to see if it imports as well (this time in OVA
instead of OVF). Fingers crossed this is fixed in a way.