If I try to include a list in a container as part of the items array, the list does not render its data properly.

The following list works correctly:

Code:
Ext.define('App.view.SpacesView', {    extend: 'Ext.List',
    xtype: 'spacesview',


    config: {
        title: 'Spaces',
        fullscreen: true,
        store: 'SpacesStore',
        itemTpl: '{name}',
        onItemDisclosure: true
    }
});
However, when I try to use a list like so, it doesn't work.

Code:
Ext.define('App.view.MilestonesView', {    extend: 'Ext.Container',
    xtype: 'milestonesview',


    config: {
        title: 'Milestones',
        fullscreen: true,


        layout: {
            type: 'vbox',
            align: 'center',
            pack: 'center'
        },


        items: [
            {
                xtype: 'milestoneslist'
            },
            {
                xtype: 'button',
                width: 'auto',
                text: 'See All Tickets'
            }
        ]
    }
});

Ext.define('App.view.MilestonesList', {
    extend: 'Ext.List',
    xtype: 'milestoneslist',


    config: {
        fullscreen: true,
        itemTpl: '{name}',
        store: 'MilestonesStore',
        onItemDisclosure: true
    }
});
I have tried everything I can think of including manually calling refresh on the list. It works if the list is the main component, but if I try to include it in the container, it does not work.