Mob reset was originally much longer, with a random component
 

For example: after a train, you used to have to wait on the other side of the zone line for a good minute or two, to guarantee safety when reentering. But in the current state it seems like mobs immediately being to path back to spawn after their target disappears. Same for gates, players dying etc. It was a scary thing to zone into LowerGuk. There could be many mobs waiting for you.

Please stop posting here without any evidence. This is not a bug report.

Maybe someone else has some. But that's how it was.