How it works when a creature or player stays outside of our point of view in Tibia but we don't lose the target on it?

Question

You probably already experienced what I gonna ask. How it is the tolerance of distance for constant target when we are following or targeting an enemy and it goes outside of our view? Sometimes I am following an enemy with attack mode for melee damage and I can sometimes follow him even when it is not possible to see the target anymore in my game window.

It happens also when I am attacking from distance and the enemy gets outside of my view. My target still works if I somehow find a way to see the enemy fast enough. If I wait for too long, I lose my target on it.

The last way that I see this effect is when an enemy is going up and down in stairs. Sometimes my target will lock for a few seconds if I change floor but return very soon to the target floor.

What is the explanation and reason for such behaviour? 

Answer 1

I've noticed that the attack mark can stay selected on the creature up to 8 sqm horizontally and 6 sqm vertically (1 more sqm of the vision area). On more sqm and it'll say "You lost the target".

The last way that I see this effect is when an enemy is going up and down in stairs. Sometimes my target will lock for a few seconds if I change floor but return very soon to the target floor.

This is interesting because sometimes it stays and sometimes it goes away immediately and honestly about this I have no clue.