Ember transitionTo route model hook not called

I have nested routes defined in my Ember app (Ember 2) as below;

this.route('workflow', function() {
  this.route('step1', function(){
        this.route('step1A');       
  });
});

Now I want to navigate to the child route & want to trigger the 'model' hook So I have

var routeName = 'workflow.step1.step1A';
self.transitionTo(routeName); //Tried Option1
self.get('controller').transitionToRoute(routeName); //Tried Option2

My question is while I do see the URL change, the 'model' hook does not get triggered.

How do I force the 'model' hook to be triggered ?

As per the doc, I think the rule is for routes with dynamic segments. But my route is a simple route.