Dead Island System Link Problem?

[zII M V P IIz]

Wasn't sure exactly where to post this, feel free to move it at will :D

I have done System Link with my brother before on Dead Island, both using Wireless adapters. His Xbox is Banned from LIVE before you ask "Why not just do it over Xbox LIVE?" But we have System Linked like 3 days ago? With the adapters no problems. All of a sudden today, I search for his game, and I don't see him at all. I made a new game at the same chapter as him, still no luck seeing the game. Anyone have any idea what the problem might be at all? What might have changed? I don't know, pretty stuck here.

[Salvia]

Make sure you'r both connected to the same router and check each others connection status.

Edit: Check you NAT Type.

[zII M V P IIz]

Make sure you'r both connected to the same router and check each others connection status.

both connected to the same router, connection status is fine.

[pureIso]

Check the Network address see if they have the same gateway or dns