Reactivating Lux's E while it's in the air doesn't reliably cause it to immediately explode

If you press E again while the projectile is in the air, it's supposed to immediately explode when it reaches its' destination.

There are two problems with this:

• Double tapping E doesn't register the second tap. You have to wait half a second before pressing E again, or it won't explode at all when it lands. This seems like a clear bug.
• There's often a 250-500 ms delay after it lands, before it explodes; but not always.

Sometimes, it does explode immediately, and it seems game-dependent. In a single game, it will either always explode immediately, or always have delay. It seems like I have the delay in 9/10 games.

The first bug isn't a huge deal, but the second bug is pretty major, because it puts you at a large disadvantage when it has delay.