Ember select prompt value is displayed though selection property is not null

Question

Template:

{{view "select" viewName="someFilter"
                content=filterContent
                optionLabelPath="content.name"
                prompt="Please selct on option"
                selection=selectedOption}}

Controller :

export default Ember.ArrayController.extend({
  selectedOption: null,
  filterContent: [{name:"option1",content:["1","2"]},{name:"option2",content:["2","3"]},{name:"option3",content:["1","3"]}],

});

On intial load when selectedOption is null prompt is getting displayed which is fine. Now I select some option and then navigated away to another route. When I came back selectedOption value is not as last selected option but default value which is "Please selct on option" (Prompt value) and not the option which was selected before navigating away.

Please let me know any thoughts on this issue.