Toss skill (pierce doesn't work)

Hello, I have a problem with skill Toss, lvl 20 Toss have 40% pierce chance, it is written in description, but I don’t see it in game. first time i thought it just invisible after pierced , but no, monsters behind doesn’t receive any dmg. I’m sorry for my english)

Playing on android,
latest update from google play market.

Known. Thanks though. :smile: