GAMEBREAKING - Takes forever to get into champ select

TL;DR : Client won't join champ select until 30-40 seconds have passed.

I have the problem since the patch. I'm using the new client.

Whenever I accept a game and get in champ select, the client freezes on the default page without loading into champ select for up to 40seconds. This is really concerning since we already have a limited amount of time in champ select, for exemple in AR URF, we have 60 seconds to reroll and pick runes and masteries.

While with that new lag, I only get 20 seconds, my client doesn't load before that.

Here's what it looks like

https://s4.postimg.org/4v3ocr9yl/Sans_titre.png