Yorick ult bug

Whenever Yorick's ultimate is pushing a lane with ghouls and without yorick, the ghouls seem to do less dmg than they would if yorick was with them.

e.g. (cant remember the numbers exactly) on my passive, it shows me that my ghouls should be doing about 95 ad per hit which they did when I was with them but when my ultimate was with them only they were doing about about 45 dmg per hit. I feel like its a pretty big deal.