Raycast calls sometime passing through Collider2D's points

Hello, I'm a Unity beginner!

The rays from my Raycast2D calls sometimes pass through points of my PolygonCollider2D and I don't know why.

Hits are marked in the following images by a small yellow horizontal line.

Here is my code:

 Debug.DrawLine(origin, new Vector3(path[i].x, path[i].y, 0), Color.yellow, 0, false);
 float angle = Mathf.Atan2(path[i].y - origin.y,  path[i].x - origin.x);
 Vector2 direction = new Vector2(Mathf.Cos(angle), Mathf.Sin(angle));
 RaycastHit2D hit = Physics2D.Raycast(origin, direction);
 Debug.DrawLine(new Vector3(hit.point.x, hit.point.y, 0), new Vector3(hit.point.x - .2f, hit.point.y, 0), Color.yellow);
 Debug.DrawRay(new Vector3(origin.x, origin.y, 0), new Vector3(direction.x, direction.y));

Is it due to bad rounding?

If so, how can I fix it?