Guard bug in For Whom The Bells Tolls

[Necramonium™]

I needed to find medicine for Captain Thomas, i need to do this by going downstairs, through a forbidden exit, the only way out, is a staircase, with a guard at the bottom of the staircase, for some reason, this guard does not react to stones being thrown near him from Henry. So the second i even try to get passed him, i am caught, if i surrender, the mission fails. Now what? I also can't kill the guard as there is no option when im sneaking up behind him.

[_Flargin]

I've got the same issue