I try to define the position of an element with
DiagramObject.Bottom
DiagramObject.Top
DiagramObject.Right
DiagramObject.Left
But the new element is always in the Upper Right Corner

I don't understand why.
My code is :
Sub UpdateActionsPlans(ByVal Repository As EA.Repository, ByVal Client As EA.Element, ByVal Supplier As EA.Element)
Dim Diagram As EA.Diagram
Dim DiagramObject As EA.DiagramObject
Diagram = Client.Diagrams.GetByName(Client.Name)
DiagramObject = Diagram.DiagramObjects.AddNew(Supplier.Name, Supplier.Type)
DiagramObject.ElementID = Supplier.ElementID
DiagramObject.right = 100
DiagramObject.top = 100
DiagramObject.left = 200
DiagramObject.bottom = 200
DiagramObject.Update()
Diagram.DiagramObjects.Refresh()
Repository.ReloadDiagram(Diagram.DiagramID)
End Sub