Can't get Post-Process effect to follow NPC

I have a Post Process effect sonar effect that I want to attach to objects and NPCs.
I have a companion character that I want the effect to activate and move around with them once the camera hits the Post Process zone.
The pulse only remains where the target started and doesn’t follow it once in the zone.
What am I doing wrong?

Please help

So it’s a localized PP effect? How are you making it follow the NPC?

It’s a PP Volume that when you enter a shockwave propagates along the walls. I used a Player Parameter Collection (float 4) and called it 'location" to try to track the moving Player or NPC’s location once these PP Volumes are entered. It works to where when I move the NPC’s starting location the effect follows the new position. It just doesn’t do anything more in-game)