Skate 3 Coop on Xbox 360

Hello, me and my girlfriend each have an xbox 360 wit Xbox Live Gold accounts, both plugged into the same router. We've been playing multiple games on live coop such as Diablo III RoS, Far Cry 4, Saints Row 3 and CoD. We never had issues and it's been playing perfectly all the time. Last week, we both bought Skate 3 for 20$ each. So far, only one of us can play online at a time. Whoever connects first onto EA nation, get to play online no troubles. The other one gets the error message that EA nation is unavailable, therefore solo play only for the 2nd player, can't join my game that I created on the other TV.... So, 2 Xbox 360, 1 router, only one can play online, the other one only has Solo play... Why? Any solutions other than Port Forwarding/Triggering, Cache Clear and Connection Settings Reset?