Windows Xen PV Network Class issue

After a dom0 update today (stable) my Windows 10 HVM pops up a dialog:

Xen PV Network Class needs to restart the system to complete installation. Press ‘Yes’ to restart the system now or ‘No’ if you plan to restart the system later.

The Win10 HVM can no longer connect to the network if I select ‘No’. It boots normally and everything seems to work except the network adapter.

Restarting the HVM to complete the installation results in failure to boot with:

Domain win10 has failed to start: Cannot connect to qrexec agent for 300 seconds, see /var/log/xen/console/guest-win10. log for details.

If i cat that log it is empty.

After several startup failures Windows will let me troubleshoot, and I can choose to boot in Safe Mode. However, upon successful reboot from Safe Mode I get the same Xen PV Network Class dialog, and the cycle starts again.

Between reboots from the Windows Recovery I get the error:

Domain win10 has failed to start: qrexec-daemon startup failed: Connection to the VM failed

Was there a Xen update in the latest dom0 update?

I used the @elliotkillick qvm-create-windows-qube to set this HVM up, but this appears to be a Xen/Qubes issue.

Doh! Seems a pihole HVM was down and not allowing network connectivity. Switching the Windows HVM to sys-firewall seems to have fixed things.