Ezreal Duskblade Bug

So, i got a funny idea. Ezreal + duskblade.

The problem is, the duskblade proc on his Q is very inconsistent. Sometimes it will proc, sometimes it won't.

Against training dummies, it will proc about 1 time per minute, regardless of vision.

Against enemy champions (veigar bot in this case), it will usually proc every time Q is up, but sometimes even when they don't have vision, the passive will not proc on ezreal Q.

To reproduce

Enter game as ezreal

Buy duskblade of draktharr

Q a target such as an enemy champion

Retain vision of them while being out of vision, ensure at least 3 seconds between Q and next Q to drop all vision

Q again.

About 30% of the time i could not proc duskblade.