I'm not being able to open the NAT for my Xbox One. I tried fowarding the ports, putting it on the DMZ, enabled the UPnP, but nothing works, it continues as a Strict NAT. I tried all of the this in two routers, a D-Link Dir 615 and a TP-Link wn840, and even put the IP of the console as a fix one for guarantee.
The only time the NAT opened was when I updated the firmware version of the D-Link, but when I restarted the console the NAT was strict again. I checked the IP just to be sure it hasn't changed.
Anyone knows what may be happening?