Taunt bug

I have this bug when having a Hireling.

When I go farming I take my Wiz hireling and my build is mostly Taunt then Whirlwind.

I noticed that using Taunt with the Hireling causes not to Taunt most of the time and the monsters just keep still so I have to go after it to kill it.

I noticed that stunned and frozen monsters cannot be taunted so I changed my build to not do that and did it also on Wiz char but it kept going.

Once I was kind alone, the Wizard was fighting a distant mob (out of screen range) and I was on another one, when I tried to Taunt I saw the monsters moving closer (from all directions) but at some point they all stopped coming to me.

Like this:
Me---------------Stopped-------------Initial Position

If monsters are stunned or frozen, they will not be moved. what is happening is that you are stunning the enemies as they are moved to you.

But when my warrior is alone none of this happens.
It only happens when I’m with my Wiz hireling that has Arcane DMG (on all items) and no Stun or Freeze effects and it happened also when the Wizzard was far away from my Warrior, so it was not dealing any damage nearby.

Does Arc have a chance to stun enemies?