So here is my problem:
even though my connection to the server should be good enough, as this picture shows, the in-game lag between my click and the server's response is very noticeable and is significantly longer than 90ms. Tried running the game on my laptop, and I still get this strange lag. So it's not my connection, not my system, not the server obviously, since no one else is complaining. So what is it then? Could it be my router?