My nodes link to other nodes hard!

I used the PolylineLinkingTool sample and do some changes;

   myDiagram.nodeTemplate =
            $(go.Node, "Spot",
                { locationSpot: go.Spot.Center },
                new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
                $(go.Panel, "Auto",//横向排列
                        margin: 5,
                        portId: "",
                        cursor: "pointer",
                        fromLinkable: true,
                        fromLinkableSelfNode: true, fromLinkableDuplicates: true,  // optional
                        toLinkable: true,
                        toLinkableSelfNode: true, toLinkableDuplicates: true  // optional
                    new go.Binding("fill"))),

                $(go.Shape, {
                    width: 20, height: 20,
                    fill: "transparent", stroke: null }),
                    new go.Binding("text")));

As you see, I just change the go.Shape to go.Picture.
Then when i make the link connect to another node, another node can not get the link.

This is the right connection.

This is my change show.

That’s my question, can you give me some advice?

I have try many times, If i do carefully ecough i can make it connected,
Of course,It is not what i want. I think i need you help ,please.

Are you using go-debug.js and checking the console log? There are some errors in your template that should be showing up in the console output.

Nevertheless I still do not understand how the template that you quote could produce the results that you show in the second screenshot.

There are some errors in my Template and i solved it.
But my question i can not make the node connected still exists.

Now,i try to use port to complete the connection.It works. Whatevet Thans your advice.