Laravel-datatables: データテーブルにデータが表示されない

Laravel 6.5.2、PHP 7.2.26（7.3.3も試してください）および "yajra / laravel-datatables"： "v1.5.0"を使用してください。
データテーブルが表示されますが、データがありません。
モデルアパートメントにはデータが含まれています。

ルート

Route::resource('apartments', 'ApartmentController')

コントローラ

<?php

namespace App\Http\Controllers;

use App\Apartment;
use App\DataTables\ApartmentDataTable;
use Yajra\DataTables\Services\DataTable;

class ApartmentController extends Controller
{
    public function qindex(ApartmentDataTable $dataTable)
    {
        return $dataTable->render('apartments.index');
    }
}

Datatableサービス

<?php

namespace App\DataTables;

use App\Apartment;
use Illuminate\Database\Eloquent\Builder;
use Yajra\DataTables\DataTableAbstract;
use Yajra\DataTables\Html\Button;
use Yajra\DataTables\Html\Column;
use Yajra\DataTables\Html\Editor\Editor;
use Yajra\DataTables\Html\Editor\Fields;
use Yajra\DataTables\Services\DataTable;

class ApartmentDataTable extends DataTable
{

    /**
     * Build DataTable class.
     *
     * <strong i="18">@param</strong> mixed $query Results from query() method.
     * <strong i="19">@return</strong> DataTableAbstract
     */
    public function dataTable($query)
    {
        return datatables()
            ->eloquent($query)
            ->addColumn('action', 'apartment.action');
    }

    /**
     * Get query source of dataTable.
     *
     * <strong i="20">@param</strong> Apartment $model
     * <strong i="21">@return</strong> Builder
     */
    public function query(Apartment $model)
    {
        return $model->newQuery();
    }

    /**
     * Optional method if you want to use html builder.
     *
     * <strong i="22">@return</strong> \Yajra\DataTables\Html\Builder
     */
    public function html()
    {
        return $this->builder()
                    ->setTableId('apartment-table')
                    ->columns($this->getColumns())
                    ->minifiedAjax()
                    ->dom('Bfrtip')
                    ->orderBy(1)
                    ->buttons(
                        Button::make('create'),
                        Button::make('export'),
                        Button::make('print'),
                        Button::make('reset'),
                        Button::make('reload')
                    );
    }

    /**
     * Get columns.
     *
     * <strong i="23">@return</strong> array
     */
    protected function getColumns()
    {
        return [
            Column::computed('action')
                  ->exportable(false)
                  ->printable(false)
                  ->width(60)
                  ->addClass('text-center'),
            Column::make('id'),
            Column::make('address'),
            Column::make('created_at'),
            Column::make('updated_at'),
        ];
    }

    /**
     * Get filename for export.
     *
     * <strong i="24">@return</strong> string
     */
    protected function filename()
    {
        return 'Apartment_' . date('YmdHis');
    }
}

見る

@extends('layouts.app')

@section('content')
    <div class="container py-4">
        <div class="row justify-content-center">
            <div class="col-md-12">
                <div class="card">
                    <div class="card-header">Table</div>
                    <div class="card-body">
                        {{ $dataTable->table() }}
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>
<strong i="7">@endsection</strong>

@push('scripts')
    <script src="{{ asset('vendor/datatables/buttons.server-side.js') }}"></script>
    {{ $dataTable->scripts() }}
<strong i="8">@endpush</strong>

ブラウザでの結果

<script type="text/javascript">
(function(window,$){window.LaravelDataTables=window.LaravelDataTables||{};window.LaravelDataTables["apartment-table"]=$("#apartment-table").DataTable({"serverSide":true,"processing":true,"ajax":{"url":"","type":"GET","data":function(data) {
            for (var i = 0, len = data.columns.length; i < len; i++) {
                if (!data.columns[i].search.value) delete data.columns[i].search;
                if (data.columns[i].searchable === true) delete data.columns[i].searchable;
                if (data.columns[i].orderable === true) delete data.columns[i].orderable;
                if (data.columns[i].data === data.columns[i].name) delete data.columns[i].name;
            }
            delete data.search.regex;}},"columns":[{"data":"action","name":"action","title":"Action","orderable":false,"searchable":false,"width":60,"className":"text-center"},{"data":"id","name":"id","title":"Id","orderable":true,"searchable":true},{"data":"address","name":"address","title":"Address","orderable":true,"searchable":true},{"data":"created_at","name":"created_at","title":"Created At","orderable":true,"searchable":true},{"data":"updated_at","name":"updated_at","title":"Updated At","orderable":true,"searchable":true}],"dom":"Bfrtip","order":[[1,"desc"]],"buttons":[{"extend":"create"},{"extend":"export"},{"extend":"print"},{"extend":"reset"},{"extend":"reload"}]});})(window,jQuery);
</script>