Event-begin playing can be turned on or off. But that’s not the problem here.
Blueprints, like any classes from code, don’t interact like what you might expect. Naming the variable the sames does not let them share the same data in memory. You have to create the object (Enemy) and then set the object as reference in order to use it correctly.
For your experience, create a thrid blueprint. Create Turret and Enemy, use “Spawn Actor” to create the reference to the objects. Then interact with them, like setting the newly created enemy object to the variable from the turret.