Kai'Sa W sometimes does not hit the Target

Hey,

was playing her on an alt and yes her damage is fine the way it is. This counter is what we needed for a feeded zed.

To the Problem:

-The Enemy Jungler was in the Bush we warded and i used my W, but it went straight through him.

Moments earlier instead of hitting the Enemy Adc it hit a Minion who was 1 Pixel in the Range instead of the Champion which was the first Target in Line.

I was wondering if this is intentional or just a Bug.

Also her Q Range is shorter as shown