Network Problem !

Dear GGG Customer Support.
Ever since the new update, I have been experiencing weird network issue. I have around 100 Mbps speed. But in-game I have around 300-400 MS PING, network.

For example I was playing Labyrinth just now, in some instances my ping is 400 ms but after i move to another room, the ping drop to around 50 ms. Usually in 3.26 League, my ping is stable around 16-20 ms.