Since when did guards get wallhacks?

Guards in WD2 can apparently see you through walls. In the intro mission, i had to restart 3 times due to guards being able to spot me through a wall and through cover, like what? There was one guard who spotted me through 2 closed doors and 1 wall. The only way i can see them in these scenarios is through the classical Ubisoft ghost vision, where every guard is red. Didn't know they had that too