Poacher's Knife does not work in Twisted Treeline

I tried using Poacher's Knife on Twisted Treeline my last game and I noticed that the passive on it did not work at all. The other items such as Skirmisher's Knife, Stalker's Blade, and Trailblazer do work. I thought it was just a fluke, but then as the game went on, I noticed that I got the same exact gold value if I didn't use smite with Poacher's Knife on the large monsters of the Twisted Treeline jungle. From what I've seen so far, only Poacher's Knife is the jungle item that doesn't work as intended on Twisted Treeline.