Seconds, Minutes, behind and minions froze during the Game

Lol has been running well on my Mac for years with the old client. I've a late 2012 version of Macbook Pro, i7 2.9GHz, 8GB RAM. Ping at 40-80, 25mbps upload and download speed with wire. Perfect till now.

After this new client came out, everything is okay till I start the game. After a little while, my champs, minions froze for a couple of seconds. Then, shit goes down. I'm still in the game but I STARTED to see I'm seconds, minutes behind the game. Why? I see everything TOO SLOW. Minions just froze on the same spot so I know I've some kind of bugs or something. When the game is done, it doesn't tell me. It just say it's "attempting to reconnect".

I tried to quit the clients many times and reconnect. It's no use. I tried to reinstall the game twice. It's still no use. It's very very frustrating.

I also tried to set my DNS to the LOL support website to 8.8.8.8 and 8.8.4.4 using ipv4, not ipv6. But my ipv6 is said to be connected automatically. Is that okay?

ANYONE can help me with this to solve this problem? Obv, I did research before I started to write this post.