Maokai's Q ability not working as intended

Sometimes when you use Arcane Smash, it does not knock back minions, champions, and neutral monsters, depending on who you use it on, even though it says on the ability information that it does.

This bug should be looked into as it is a huge nerf to his jungling role (as the loss of a knock back increases the amount of dps Maokai would normally receive had the knock back gone off properly) as well as his team fight presence.

I don't have any sort of program to record this with. You can replicate this in a customs match, though. I have done so multiple times.

Riot, would you mind looking into this bug? Thank you!

I have posted this on Reddit as well so that Riot can gain more visibility on this issue.