Severally disconnected fom server last days, why?

In the last few days I get randomly disconnected from the server and for no reason. I would say that it happens more often than at the very beginning and it also happens to other members of our guild. The problem has been happening since the last update, I would say when AQ creeps were spawned into towns. Disconnection happens often, 4 times a day or more, and it’s very annoying, especially when you’re in a dungeon.

I want to ask if the other guilds also have this problem? Alternatively, what is the cause, can it be removed and how?