[GAMEPLAY] Anivia's Q hit box bug.

Recently I bought Anivia , and I've noticed that when I use Q and I land it perfectly or hit another champion with it, sometimes it won't occur as a stun, even though it damages them and explodes on them. Now generally I'm getting annoyed with this since it's caused a few issues. My point being, everytime you use Q and it lands, sometimes it won't stun the target.