Update EmberJS SortableMixin Based Component on content change

i have a simple component that extends Ember.SortableMixin:

export default Ember.Component.extend(Ember.SortableMixin, {
    sortProperties:  ['points:DESC']
})

It displays points and name:

{{#each arrangedContent as |user index|}}
    {{user.name}} {{user.points}}
{{/each}}

and its included like this:

{{quiz-leaderboard content=model.participants}}

If the points now changes there are updated in the view, but the sorting is not refreshed. How can i manage this? Thanks for any help, Jan