Xbox not showing up in Port Forwarding List

I have two Xbox's.  One of them shows up in the xFi Port forwarding list allowing me to add/delete port fowarding options.  The other Xbox does not show up in the Port Forwarding list so I cannot create port forwarding rules for it.  It shows as a connected device in my devices list and my son plays on it daily so I know it connects just fine.  I've tried connecting it directly to my router and disconnecting all other devices.  I've tried assigning it a static IP4 address.  Nothing has seemed to work to get it to show up in my Port Forwarding list.  Any help would be appreciated.