Games ends before it begins

A few times now i have pressed the "fight" button in an event. The game flickers as though it is going to load the match, then it goes back to the node screen and says "claiming match" and i effectively lose that match.

I find this happens if u turn off ur phone/tablet screen on the node screen and come back a little later and try to play a match. ie the game is stilll running - turning on the screen, pressing the node, then pressing the fight button.

It flickers to start a match then crashes back.