Sort Descending broken #366

I'm using Laravel 5 for the first time and am using this plugin to pull data from a MySQL database.

The following code sits inside my controller:

return Datatable::collection(Invoice::all(array('id','date_issued','date_due','user_id','total','status')))
        ->showColumns('id', 'date_issued', 'date_due', 'user_id', 'total', 'status')
        ->searchColumns('id', 'date_issued')
        ->orderColumns('id','date_issued')
        ->make();

This code sits in my blade template:

{!! Datatable::table()
        ->addColumn('Invoice ID','Date Issued','Date Due','Client','Total','Status')
        ->setUrl(route('api.invoices'))
        ->render() !!}

The datatable displays correctly initially, but if I click the "id" or "date_issued" table heading to sort "desc" I get no records, just the message: "No matching records found". If I click the heading again to sort "asc" the records come back.

I can see the AJAX requests via Firebug. The only difference to my eye is sorting "asc" returns an array and "desc" returns on object. I'm not sure if I'm going wrong or if this is a bug...