DC every 7-8 min mark of the match

Greetings HotS team, I noticed that I always get disconnected to any game mode (qp, vs ai, ranked, brawl) when it reaches to 7-8 min mark. My png is fine and also I set the graphics to medium-high. It takes me a while to reconnect and sometimes I get dropped. How do I fix this? Pls help T_T