Ember model not saving changes from itemController

In a parentController I'm trying to save changes that are made in an itemController. I can see that the model is changed in the store but when I save the model the changes are gone. The team model has a members hasMany relationship and I. All of this happens in a modal dialog.

My code is something similar to this:

// editing in the itemController

    .....
    var members = this.get('model.members'),
        currentMember = this.get('activeMember.content'),
        isChecked = this.get('isChecked');

    if (isChecked === true)
        members.pushObject(currentMember);
    else 
        members.removeObject(currentMember);
    .....

-

// saving in the parentController

    .....
    this.store.find('team').then(function(team){
      team.save();
    }
    .....