Grand Duke Ravengard

So…

This is my second playthrough, and to be different from my first one, I’ve killed Gortash before Orin.

I did the iron throne, saved Duke Ravengard, and then snuck into Wryms Crossing up the Gortash to kill him.

However, after finishing the combat I saw on my journal that I killed Duke Ravengard, went back to discover he was alive when I entered wryms crossing, but then as soon as I got to the top floor (the balcony outside) the notification that he died came up.

Does anyone know why this is happening? Is there a combat I absolutely have to do before Gortash, I pretty much did everything I did last time, expect I did the combat on the floor below the first time.

Is this a bug, should I just continue?!