There is a bug of ranking LP

There is a bug. If a teammate suddenly afk without any reason after 5 mins, for we four, it will be a game which must(99%) lose, I think it is unfair that we have to lose LP for that off-liner. I think maybe the way to fix it is add all LP losing of five together and make this sum become that afk player's losing to punish. Or at least don't take out our four's LP. As a player, I think losing a game is normal but it should be a fair game. Our LP is taken by a unfair game!