Executor 3rd ability not working?!?

I've been using this ability and getting super frustrated because the taunt isn't working. If I apply this to a bounty hunter, they're supposed to taunt for two turns, yet they are not.

Not sure why this is happening (or not happening), but it's super frustrating to heal a tank that you want taunting, and the taunt buff doesn't show up and then someone else on your team dies.

Please advise.