Zach if you can still reproduce, can you provide the libvirt XML and the associated qemu command line from /var/lib/libvirt/qemu/$VMNAME.log for the working (virt-install) config and the non-working (virt-manager) config?
Zach if you can still reproduce, can you provide the libvirt XML and the associated qemu command line from /var/lib/ libvirt/ qemu/$VMNAME. log for the working (virt-install) config and the non-working (virt-manager) config?