Ranked Champion select freeze and normal game decline by itself

Lately these past months my lol has acted quite wierd. Sometimes when i que up for a normal game whenever a game is foun dit just automaticly declines by itself and says that an active game was not found. And whenever i play ranked the accept thing works fine but when i get in champion select it just freezes and after some seconds kick me because i couldnt pcik/ban a champ bcs my game froze. Iw lost a bunch of ranked points and have waited such a long time, and i dont know how to fix this so please help me :((((