Behavior Tree slow Perception

I recently setup hearing and sight perception on an enemy character to notice when the player is nearby, and set a blackboard key as the target. Unfortunately my behavior tree takes some time register the change and perform the next task. The tasks are supposed to switch based on whether or not the target blackboard key is set. I have tried increasing the sensing update, but there doesn’t seem to be much of a difference. Is there a better way to transition to another task once the blackboard key changes?