How to correct spawn pawn with AI?

I create a pawn,called it ZombiePBasic,set AIController to ZombieBasicAIController

That just run Behavior Tree.

In service CheckZombieState

i do next:
On zombie creating set state to idle,get pawn from ai contoller and bind event to pawn.
When i put my zombie on the level,it works great.But when i tryed to spawn zombie with Spawn Actor from class, i can’t get pawn from controller.
My spawn looks like

How can i fix it?