I am try to get an Open Nat on a PS4 and Xbox One at the same time.
Router TP-Link W9980
The Xbox One Requires 3074 for communications
The PS4 Requires an Activision Port 3074 but they do say open 3075 or 3076 for multiple console this does not work
I have tried DMZ with the Xbox One while the PS4 has 3074 and the Xbox is Strick
The closest I get to is moderate on the PS4 but its lagging.
I was thinking is this possible since the Xbox One is IPv6 Compatible would setting the Xbox up as IPv6 and the PS4 up as IPv4 work?
Spent a good few hours today trying to get an open NAT on both console without success.
I managed to get an open NAT in games but in the Xbox Network setting said it was Strick for a few OS features. That was just by using UPnP.
Port triggering with and without DMZ would equal in 1 console being open and the other one being modorate. First console started gets an open NAT.
The issue seem to be with Port 3074 because the PS4 needs it for Activision Games and the Xbox needs it for communications.
Activision does state port Forwading 3075 or 3076 should work but nothing helps.
I am thinking of upgrading to a newer VDSL2 Router/Modem for IPv6 but the PS4 does not support this as of yet but the Xbox One does.
A long shot but would it be possible to use IPv4 with Port Forwarding on the PS4 and use IPv6 on the Xbox One since there is no NAT restrictions?
Archer VR900 or Archer VR2800
I imagine a new router with the Xbox using IPv6 would be the answer to your problem. TP-Link should have the IPv6 /56 prefix issue rectified on new devices. The firmware date for the VR2800 has a Published Date of: 10/01/17. They have been working on the firmware fix for a while now and have said they were concentrating on new devices first.
You could contact their support centre before hand to confirm, (details on web site). They have a beta firmware for the VR 600 that works fine at the moment so possibly the VR 900 is the same.