3 xboxes in one house. problems with Dayz

I have 3 xboxes on my network. I followed the instructions found online for enabling uPNP and setting up rules to allow only those xboxes to use that services. Everything works well for Minecraft and Halo. I have all the xboxes using alternate port selection. One xbox shows up and OPEN NAT and the other two show up as moderate. This has worked well until we started playing DayZ

With DayZ If one xbox is playing a game on a public server the other 2 xboxes can not join the game. How do I begin troubleshooting this?

I have not really done much with XBOX might want to try their forums https://forum.netgate.com/