I think that the DHCP messages you saw when you switched to Merlin's firmware has given more clarity on the problem. I believe that those messages are suppressed by default in the stock firmware which is why you hadn't seen them before. Although this still doesn't explain why it worked at your neighbour's with the same hardware and firmware.
We had suspected that it was a DHCP issue. It appears that even though the RIG is asking the router for an IP address (DHCPDISCOVER) it is deaf to the reply that the router is sending it (DHCPOFFER). There are two ways the DHCPOFFER can be sent to be RIG which should be indicated by the RIG itself, broadcast and unicast. It's
possible that RIG is not following the correct procedure here. As an experiment you could try logging into the router via SSH and issuing the following temporary commands:
Code:
killall dnsmasq
dnsmasq --log-async --dhcp-broadcast
Test the RIG by turning it off and on again. Does it get an IP address straight away?
Reboot your router to undo the change you made.