LineRenderer moviment problem.

Hi to all, i'm developing a 2d game but i've a problem, there's my code (it's an a prefab object):

     GameObject go = new GameObject();
     RectTransform rect = go.AddComponent<RectTransform>();       
     go.name = "moviment_" + data.mission_uid;

     LineRenderer lR = go.AddComponent<LineRenderer>();
     lR.material = new Material(Shader.Find("Particles/Additive"));
     lR.SetColors(Color.yellow, Color.red);
     lR.SetWidth(10F, 3F);
     lR.SetVertexCount(data.movimentList.Moviment_Step.Count + 1);
     lR.SetPosition(0, _city_origin.transform.position);

     int i = 1;
     foreach (Moviment_Step ms in data.movimentList.Moviment_Step)
     {
         GameObject city_to = GameObject.Find("obj_" + ms.object_id_end);
         MapButtonController _city_to = city_to.GetComponent<MapButtonController>();

         lR.SetPosition(i, _city_to.transform.position);
         i += 1;
     }

     go.transform.SetParent(map.transform);
     go.transform.position = new Vector3(0, 0, 1);

when i run these code the line was draw nice. in the position that i need. u can see the the linee was created in the right parent gameobject.

but when i move the parent (is in a scrollrect) .. all object are fixed on but not the lineRenderer.

any idea? thank you!