Going to point something out.

there is a feature in aoe attacks that im going to dub for this explanation-attack lock. There is a point between the start of the aoe and the attack itself after the circle disappears in which youll the atack will "lock-on" per say. At that point, it doesnt matter if you are out of the circle-zone or not. You'll be hit with the attack. I've seen that most victims of attack lock are those that try to finish casting/attacking before moving. Its matter of not moving to beat the attack lock timer.

Now I will say that attack lock can be frustrating/unforgivable at times. there are some monsters with an aoe circle big enough to where you have to move as soon at it shows or youll be locked. Now if you're out of the circle and its still up for a tiny bit, then that is probably not attack lock, but instead a bug. If you move out of range as the circle vanishes or vanishes immediately after you move out of range, thats attack lock.