There's sometimes a lack of precision when the defending player is close to the attacking player... I had 2 or 3 goals/passes not counted because the defending player was the passing zone...
Just had a boring bug : I made an assist - the guy i've passed the ball to scored - but it hasn't been counted, and worst of all because of that i'm being sent on the bench AND i lose the match...
Not logical. I lose against 18th being 2nd, I get +1 by everyone. I win against 7th being 3rd, doing an assist, I get -1 by everyone... this kind of things happens often. And the assist is under-valued.
Check your flash storage, right click in game, Settings, and check the slider.