UNABLE TO CONNECT TO THE SERVER

it is my third time that i encountered this problem. I tried my best to back to the game, follow any advices form google, but it doestnt work. As a result, I was placed in a lower priority queue. 20mins waiting time. However, it has nothing to do with my network because i can play the next game normally. Tis problem alwaays happens suddenly, so plz tell me what to do next. BECAUSE IM NOT A DESERTER.