DMZ and rebooting router solving issues, need help

Hi guys how are you?

I need a help here and i`ll try to describe the best i can since my english is not good

I have a Rt-Ac3200 one with load balance enabled and the main PC at DMZ, playing for example Black Ops 3 my NAT is open that is the correct, but when i try to find some match sometimes i can`t find anyone, i thought it might be a game issue but now comes the deal

If i rebbot the router the game starts working again finding match or if i simnply disable dmz and enable again at the...

DMZ and rebooting router solving issues, need help