Client Lag when open browser

My client was lag and I have been suffering it since the new client released. I just think it's just it a bug and I just have to wait hopelessly for a fix. I have 16GB Ram and so I never ever think that it could cause lag. One day, I realized the lag only happens when I open the browser (any kind of browser you can think, Chrome, Firefox, Opera, Edge, and even Internet Explorer). I only use 9gb of ram while opening both League and browser. My client was running super smooth if I close my browser. You may say the ram is not enough, but no way. I tried to open GTA V Online and browser closed while playing League (sound crazy but just to test if it's true because of browser or what). Although my lap was running at full usage, League was running smoothly without any problem. Now, I have to use my phone to play music while playing League ban/pick. My in-game experience have no problem with the browser. My ping is 60ms most of the time and FPS is locked at 60.

It's very annoying and seems Riot don't care much about it since I saw a lot of posts talked about it and Riot just come in and post a support page there then leave as nothing happened. If the problem was not solved, they will say something like "We are working on it and hoping it works." I just want to throw a into their face when I saw that. Trust me, I tried everything on the support page, even the not recommend way like disable the Firewall or clean re-install by Hextech Repair Tool.

Does anyone having the same issue or having the way to fix this without closing browser? I mainly use Chrome but I don't mind to switch to any other browser so I can play Leauge smoothly.

I use MSI GS40(i7-6700HQ, GTX 970M, 16gb Ram, SSD Samsung 970 Evo (game, win, and browser are installed on SSD))