Ember not updating template when attribute of controller is modified

I have one attribute which I'm modifying through an action, but Ember is not updating the rendered template.

My controller:

selected_rows_id: [],
actions: {
    selectRow(rowId) {
        let selected_rows = this.get('selected_rows_id');
        selected_rows.push(rowId);
        this.set('selected_rows_id', selected_rows);
    },
}

In my template I'm using to show my elements

I've created a twiddle to demonstrate what I did