Ember.js: Related model empty when using multiple models in a route

Really stumped on this one..hopefully I can explain the issue clearly.

I'm loading multiple models in the EditRoute and displaying data from the artist model perfectly. Artist Genres is a related model and also displays fine in the template.

Model:

var attr = DS.attr,
belongsTo = DS.belongsTo,
hasMany = DS.hasMany;

App.Artist = DS.Model.extend({
    description: attr(),
    groupname: attr(),
    artist_genre: hasMany('artistGenre', { embedded: 'always' }),
});

App.ArtistGenre = DS.Model.extend({
    name: attr(),
});

App.Genre = DS.Model.extend({
    name: attr(),
    displayorder: attr(),
})

Route:

 App.EditRoute = Ember.Route.extend({
    model: function(params) {
        return Ember.RSVP.hash({
            artist: this.store.find('artist',App.CurrentProfile.id),
            genre: this.store.find('genre'),
        });
    },
    setupController: function(controller, model) {
        controller.set('artist', model.artist);
    }
});

Controller:

App.EditBasicInfoController = Ember.ObjectController.extend(App.ArtistEdit,{
    artist: null,
    genre: null,
});

Template:

List OF Artist Genre (Related model):
{{#each genre in artist.artist_genre}}
    - {{genre.name}} </br >
{{/each}}

<div class="row">
    {{input value=artist.groupname placeholder="Enter Artist name"}}
</div>

The issue appears when I set the controller "genres" property that I loaded in the route model().

App.EditRoute = Ember.Route.extend({
    model: function(params) {
        return Ember.RSVP.hash({
            artist: this.store.find('artist',App.CurrentProfile.id),
            genre: this.store.find('genre'),
        });
    },
    setupController: function(controller, model) {
        controller.set('artist', model.artist);
        controller.set('genre', model.genre);
    }
});

The artist data (artist.groupname) still works properly but the artist genre (related model artist.artist_genre) data is now empty in the template. Why would setting an additional controller property make the related model empty in the template? I still see the actual data in ember inspector.