Why is while overlapping detection not working for me?

I’m trying to learn how collision works in UE4, and reading the Doc. is not helping with this problem.
I want to make a fighting game, and I need the collision sphere to become active while overlapping the enemy’s hit Sphere. This is skipping the “on overlap start” somehow, and I have Constant Collision Detection enabled on the shapes.

I’m using a variable to say if an action should be taken during overlap or not, during the hit frames of an attack but not during the startup or recovery.

If the variable says it’s active before touching the enemy’s collision sphere, the action works.
If the variable is off when it enters, and turns on while still inside, the action does not work, even though, it is still overlapping.

What am I doing wrong?

The test I’m using is with two balls, like the rolling demo. With large hit spheres around them, if I’m rolling forward, the attack should be active. If rolling sideways, the attack is off.

Now if I get close the the enemy while rolling sideways, so they are overlapping collision spheres. Then try to move forward to activate the attack, the collision doesn’t work.

Never mind, figured it out, I used that same variable to run the Set Collision Enabled function when I need it.