Replacement router here fired up first time.!

I've got a similar issue to mbaker171. I am on VirginMedia and want to change my current 2820 for a 2860. I use a superhub3 in modem mode. Everything works fine with my 2820. Under the WAN settings it is set to 'obtain an IP automatically' and it uses 192.168.100.20 and connects to the gateway (the SH3) on 192.168.100.1 which is fine. After 15 seconds or so the SH3 wakes up and the IP address changes from 192.168.100.20 to my VM WAN IP address; 77.98.82.xx (and the gateway address changes to a VM gateway IP, 77.98.82.1). Connection is made and everything is fine.
With the 2860 the first part works fine; I can see the WAN IP is 192.168.100.20 and the gateway is 192.168.100.1 but the second part fails. So after 15 seconds instead of the WAN connection being made the connection just drops completely.
I can't see a reason for this; all the parameters seem identical for both the 2820 and 2860. Any ideas?

I updated the firmware and then found the time was wrong. Updating that seems to have got it working...

My replacement router is now not working in exactly the same way my first router failed. I have attempted to raise a ticket with Draytek and I hope they can work with me to resolve. Otherwise this router will also be going back. I'll have to move another supplier! Shame as I have been using Draytek for decades.

Well loaded the 3.8.8.2_BT firmware and it fired up first time. Wonder how long this will last!