Hammer of the Ancients doesn't hit the enemy

Hi there!

i’ve played the sorceress and the rogue to level 100 yet and leveling the barb right now.

So i tried some different builds and really love the Shout Hammer of the Ancient build…
BUT
Everytime i’m in a 1vs1 fight like bosses or even normal enemies it feels like i do no damage at all…

my first thought was, it’s the Heart of the Barber, so i took it off to test and again some hits do not make damage!

I created a new Barb played him until i i can use the hammer and the same issue.

It looks like i’m standing to close to the enemy and swing the hammer behind them.

Can someone confirm or tell me if this issue is known?