I did try this and result is the same. The PVA is actually calculated from both sides of the forward vector of the actor so a 90 degree PVA is 90 degrees to both sides, giving the actor a 180 degree field of view while a 180 PVA would give the actor a full 360 degrees of sight. The debug editor displays this with a green line (which should be different by default for clarity) that you can see in the images running perpendicular and through the actor in the sphere of its sight radius.