Collider2D.GetContacts() always returns only 1 contact

I try to get the contact points of 2 2D Colliders (circle and box) which are moving towards each other and eventually overlap. The Maximum Amount of Contact Points would be 8 then. So I am saving the contacts in an Array but when colliding, but there is always only 1 contact point in the array.

Code (CSharp):

1.  
2. void OnCollisionStay2D(Collision2D collision)
3.     {
4.         collision.GetContacts(contacts);
5.  
6.         foreach (ContactPoint2D contact in contacts)
7.         {
8.             Vector2 hitPoint = contact.point;
9.             Debug.Log(hitPoint.ToString());
10.         };
11. }

 

Unfortunately I cannot edit that post. So additional Information here:
To visualise my problem you can see both shapes in this image. At this point there should be 2 contact points, I assume.



But my array looks like this: