[BUG] NPC's wont attack back?

Before I get into all this, you'll have to forgive me as I'm new at WoW servers. I'm used to hosting an Unturned server or an RSPS.
But basically I'm using WoDCore and for some reason when I attack a NPC they don't attack back, and what else is they also heal too.

I have a video uploaded for what happens, if you would like for me to post it let me know :).

Please help.