Ok! That did exactly what it was supposed to do! So we now know that IsAttacking is False before pressing the button, and therefore it is flowing through the FALSE part of the branch.
Let’s set the object type and see if that makes it visible. It may not be tracing because it has nothing to look for.
In your Object Types variable, at the bottom of the Details window, you’ll see that you can add an object type. I don’t know what your enemies are, but whatever they are you should add that to your object types list with the “+” button!
Edit: It doesn’t really have to be specific, you could use Pawn, Character, or BP_WhateverYourEnemyIsCalled