Raptor Buff and Bushes

I don't know why that if you have the Raptor Buff, and there is an enemy ward in a bush you have vision of but are not in, the ward does not show up. You have to be in the bush for the enemy ward to show up even if it was in the radius of your Raptor buff when you weren't in the bush and you had vision of the bush. Raptor buff should make all enemy wards visible in it's radius as long as you have vision on where the enemy ward is placed.