Same here!
With any char bot will do it - i think he looking into memory and see that enemie is there, but he can't check if the enemie is invisible (inside earth, like a Statue in Library, etc).
Don't know if this can be fixed =/
Same problem here!
One more bug that i found - sometimes enemies are right in front of you and he keeps clicking melee attack and don't hit the enemie!
When this "bug" happen, i just leftclick with mouse (without turn off the bot or move mouse) and he start to hit it.