Hey folks,
This one is driving me mad. Managed to get this UDM SE setup yesterday and it connected to the internet eventually fine, that lasted for about 8 hours when it suddenly just lost its WAN address. It eventually started connecting and disconnecting, every 30 seconds or so.
I factory reset the thing, and now it won't pick up an IP address again at all.
Setup
BT FTTC Connection in -> Vigor 130 in MPoA bridge mode -> UDM SE via WAN (port 9)
I have tried resetting the Vigor 130, and that was to no avail.
I am fairly confident in the fact that it is not an issue with the Vigor 130, as I am directly connected to that now and have PPPoE setup from my machine and that has given me the internet in which I write this.
This makes me firmly believe it has something to do with the UDM,
What is a UDM? Can you try with a BT Hub in place of the Draytek Vigor?