Biggest problem with new client

So I do like the new client and the setup with it and all. But I have only one major problem with this client.

On the old client in champ select I was able to run it with no lag at all. Now with the new client champ select, I'm lagging so hardcore it isn't even funny. I'm literally bashing my head into the keyboard in the hopes that my ban or pick goes through. I can still pick my runes alright but when I try changing up my masteries, it doesn't work. I can't remove mastery points, I can't put mastery points in. I can't even change the page. I'm literally stuck with the same keystone every match because I'm not allowed to change it. IDK if this is a bug or what but ya.

I guess it's really two problems but they both appear in the champ select phase and that's what I'm getting at.