Attacking-Moving Issue

Hi, this is my first post and I am a new but kinda experienced player but I do not think this problem is normal. I am unsure if it is a bug or not. Here we go:

TL:DR: I am currently playing Cassiopeia and when I cast skill (Q) to a champion that is out of my range, after casting that skill, when I use my Twin Fang (E) at the moment the opponent is in my range, "Cassiopeia moves towards the cursor/champion even if I do not click".

First, I do not know if this problem is about Cassiopeia, or LoL client, or my Laptop or even if this is a problem. Maybe this bug is just about (E) of Cassiopeia, as I said, do not know. Suppose that X = Cassiopeia ) = Cassiopeia's Q range O= Minion

• = Minion with cursor on it Z = Opponent champion

• = Empty space

It exactly goes like this (I could not find a better way to describe this)

First, I see the minion which is out of my range

X-----)--O-----Z

Then, I hover my cursor on it and cast (Q) (In smartcast, same thing happens but a little bit different. I can further explain if you want, I do not want to prolong it.)

X-----)--+-----Z

Then, Cassiopeia starts to walk in order to cast (Q)

X----+)-----Z

And here the issue starts. Now I cast (E) on the minion, which is in range. But instead of standing and casting the skill, Cassiopeia walks towards the minion/cursor or even maybe the opponent champion. As I said, I do not know what triggers this.

X+-----Z //////instead of/////// X----+)-----Z

You might think that it would not affect gameplay too much but when you are in a teamfight, you try to cast skills with Cassiopeia and she ends up near Darius, which is a problem for Cassiopeia since she is a vulnerable ranged champion.

I really looked in every corner of Internet for this, tried toggling casts on/off and making matches vs. bots to solve this but it did not help, thus, I decided to write here. I am asking for your help.

Regards.