apologies, that seemed to fix it in dev on our no-sub box but the problem remains on the Prod sub machine including the script failing and the flashing screen. Very odd, I've been running no-sub boxes for a good while now and never seen this.
The Ubuntu kernel is different from a Debian's. If also the Ubuntu VM is stuck with network issues, then it looks more like a general network issue. Did this happen before? If not, what has changed since then?
On a fresh install, you will find the vmbr0 bridge to have the IP address, netmask and gateway set (from your input on the installer). In the resolv.conf the nameserver and domain you provided will be set.
Thanks for the update John, would you mind adding "[SOLVED] " in the front your thread subject name? That way everyone knows there was a solution. Thanks