Collision2D Points Outside of Collider Bounds

Hi there, I'm trying to detect the points at which two collider2Ds collide. My problem so far can be seen in this video showing the error.

The white line traces the points where the collisions are currently being detected. Why are the detection points appearing outside of the bounds of my colliders?

The code:

     void Start()
     {
         cp2 = new ContactPoint2D[5];
         bc = GetComponent<BoxCollider2D>();
     }
 
     void OnCollisionStay2D(Collision2D col)
     {    
         bc.GetContacts(cp2);
 
         foreach (ContactPoint2D cp in cp2)
         {
             Instantiate(circle, new Vector3(cp.point.x, cp.point.y), Quaternion.identity);
         }
     }