Stuff Fibre Xbox One NAT type unavailable - cannot resolve

Hi there,

I was with Vodafone using Fibre and had no issues using my Xbox One and my NAT was always open. I recently moved house and changed providers to Stuff Fibre and since then my NAT is showing as 'Unavailable' and I'm getting the error "Cannot get a Teredo IP address".

I'm using the standard router provided by Stuff (Asus RT-AC59U V2) and connected via ethernet cable. I did also try on WIFI with the same issue.

I have tried a number of things to resolve it including:

- Port forwarding all Xbox suggested ports- Binding IP address to my Xbox MAC address- Turning off IPv6 (now set to "Tunnelling")- Turning off UPnP and then back on- Updating router firmware (now version 3.0.0.4.386_21649-g7401a04)- Turned off router firewalls- Tried using DMZ

I have managed to get it open on about 3 occasions (in the evenings) and then in the morning its unavailable again (not changed anything on my end).

Any assistance would be greatly appreciated as Stuff Fibre Support, Xbox Support and Asus Support all so far have been unhelpful and pretty much suggesting standard troubleshooting I have already tried, or telling me to call each other.

Thanks in advance

Evan