I have the same issue. I DC at least once per game. Most of the time it is once per game.
On top of that, I dont even (rather not willing) to play ranked anymore with that issue. In two games just before my team won the game, I dc'ed. When I reconnected the game was over and in my match history I was labeled as "Leave" on those games. Ridiculous. Im sure you can even get banned for that, so I wont risk playing ranked.
I have no idea how to solve this. And I tried everything I could think of. (and im a tech geek)