How to modify the diagram when loading Json into the model

I can save the GraphLinksModel of my diagram to json as shown below

  public save() {
    this.savedModel = this.observedDiagram.model.toJson();

  public load() {
    this.observedDiagram.model = go.Model.fromJson(this.savedModel);

the Json is bound to a texbox in which I can modify it. For instance I may want to change the color of a shape from yellow to red.

Then I’d call the load() function, but the diagram is not updated. I see that diagramModelChange is called (the event bound to modelChange event of the diagram)

<gojs-diagram #myDiagram [initDiagram]='initDiagram' [nodeDataArray]='diagramNodeData'
                    [linkDataArray]='diagramLinkData' [divClassName]='diagramDivClassName'
                    [modelData]='diagramModelData' [skipsDiagramUpdate]='skipsDiagramUpdate'
  public diagramModelChange = function (changes: go.IncrementalData) {
    this.skipsDiagramUpdate = true;

     this.hasChanged = changes !== null;

    this.diagramNodeData = DataSyncService.syncNodeData(changes, this.diagramNodeData);
    this.diagramLinkData = DataSyncService.syncLinkData(changes, this.diagramLinkData);
    this.diagramModelData = DataSyncService.syncModelData(changes, this.diagramModelData);

Are they any extra steps to take when using the angular wrapper ? I should be able to update the diagram when reloading the modified json, right ?

sorry it turned out to be a silly mistake. My textbox binding was incorrect

 <textarea id="mySavedModel" style="width:100%;height:300px" [(value)]="savedModel"></textarea>

should be

<textarea id="mySavedModel" style="width:100%;height:300px" [(ngModel)]="savedModel"></textarea>