Opponent disconnection reason
Now few times I have seen when I play any match with opponent with higher OVR & against them when I score a goal they get disconnect from the match. So one reason wud be internet connectivity, 2nd ...
Forum Discussion
From your description, it sounds like they're just disconnecting because they don't think they can beat you, which is an accepted part of the community and is encouraged to let people not waste time if they're clearly going to win a match. If, however, you mean they're performing a disconnect when you're winning and the game credits you with a loss or draw, that's a fairly well-known glitch players have used for a while, I think specifically on PlayStation, to avoid having a match count as a loss despite losing - this is just an unfortunate part of the community; those people deserve to be banned.
Game has reached the end of it life cycle and there are still bugs and glitches from day one.
