[Client] Client doesn't work properly during champion select, then times me out

Sometimes when I get into a champion select, the game will blackscreen and then if I close the client and reopen it, it won't let me join a game for a certain amount of time. It doesn't happen very often, so I don't know if it can actually be replicated in a reasonable amount of time.

In the past (and probably due to my internet connection then, but my internet is fine right now) I have had such bad lag in champion select that I get kicked for not selecting a champion.

I'm not sure if this is related or not, but sometimes at the end of a game (after victory or defeat) the button to exit the game and get back to the client will not show up, and while it doesn't ban me as if I had left during a game, I have to quit out and reopen the client and don't get to look at the graph/IP gained/champion exp gained.