Many years ago they made a change to control undead to stop necromancers from leaving strong mobs at cabals or on the roads. Vampire Control undead especially edged to be stronger is lasting longer than the mob will stay with me. It wanders off while I still have control of it. Can we look at the timer for how long mobs will stay before wandering off when controlled. Vampires didnt exist when the change to control was made.

*SNIP LOG*

So the specific echo you showed happens only when a mob was summoned.
So don't do that and it won't happen.