The last four matches in a row that I've won, I've gotten disconnected from server and not received credit for the win. Four in a row. Funny as it does not happen when my team loses.
So frustrating...
From what I have been reading people think it's from the the supply drop outfits and helmets when you are in the winners circle. Try going back to all default outfits and cammos on your classes and see if you get disconnected the next time you win.