Yet Another 2D Collider Question

I am trying to make a projectile that deletes itself upon collision. I do not think any collisions are occuring. In Image 1, you can see a white ball which is firing small white balls at the maroon boundary. The balls stop at the maroon boundary and kind of "vibrate" while their x position continues to increase in their Transform component.

The projectiles have rigidbody2D and a collider (image 2). The boundary has a collder.

The layers are both 0, and that layer is enabled in the layer collision matrix.

The projectiles have the following in their script:

 void OnCollisionEnter2D(Collision2D col)
     {
         Debug.Log("Text: Collision Detected");
         Destroy(gameObject);
     }

No log is written when they stop and vibrate at the boundary. Any ideas?