Target Actor returning none even though my AI is moving towards player character

I am trying to set up a basic AI move to player if detected system.

I have run into a bit of a problem where my blackboard hits an error (target actor stays as none) except my AI is still moving to my character.

This may seem fine but as soon as i try to implement any other logic the whole blackboard just refuses to work.

Has anybody else had a similar problem to this? any help would be appreciated.