Ranger pets and KD
Why should pets be falling down with their owners? They are not exactly on a leash or something.
They stay with the enemy for quite some time even if you move away which is imho the right and expected behavior.
(Because you can use your pet as a tank and you really don’t want the tank running from tanking a boss straight to you when you decide to kill some trash mobs further away)
For the swapping, sounds like a bug, because like you said, normally they spawn at the players location.
So the first point isn’t a bug it’s intentional i’d say. The second one could be a bug maybe it was just a minor glitch.