TextBlock alignment on spot node resize

I have the following node template.

var nodeTemplate =
  $(go.Node, "Spot",  // the whole node panel
    {
        selectionAdorned: true
      , resizable: true
    }
    , $(go.Shape, "Rectangle", 
                {
                  fill: "lightgray"
                , strokeWidth: 2
                }
      )
      ,
      $(go.TextBlock,
        {
          name: "TitleTextBlock"
        , alignment: new go.Spot(.5,1,0,15)
        , alignmentFocus: go.Spot.Center
        , font: "bold 16px sans-serif"
        , editable: true
        , text: "some node title"
        , background: "lightcyan"
        }
      )
  );  // end Node

I thought a Spot node was perfect because one can align the textblock outside of the main shape (the rectangle). as you can see I have a node title positioned underneath the rectangle.
However as soon as I resize the node and make it bigger, the textblock disappears and is no longer underneath the rectangle? How can I allow the resize and keep the text block where it should be?

Give the Shape a name and then set Node.resizeObjectName to that name.

Perfect. Thanks.