使用group by和union时，Laravel分页不起作用

// 执行带有group by和union的查询
$query = DB::table('table1')
    ->select('column1')
    ->groupBy('column1')
    ->union(DB::table('table2')->select('column2'));

$results = $query->get();

// 手动进行分页
$page = request()->get('page', 1);
$perPage = 10;

$total = $results->count();
$offset = ($page - 1) * $perPage;

$items = $results->slice($offset, $perPage);

$paginator = new \Illuminate\Pagination\LengthAwarePaginator(
    $items,
    $total,
    $perPage,
    $page,
    [
        'path' => request()->url(),
        'query' => request()->query(),
    ]
);

// 获取分页链接
$paginator->links();