If the starting value for pagination is changed in the URL, the correct content of the displayed page is not always shown.

If the 'start' value is set to 2, page 1 is displayed in the pagination. A portion of page 1 and page 2 is displayed in the list.
My modified 'validate_start()' function for 'pagination.php' ensures that the content of the displayed page is always shown.

    public function validate_start(int $start, int $per_page, int $num_items): int

    {

        $start = $start >= $num_items ? $num_items - 1 : $start;

        $start = intdiv($start, $per_page) * $per_page;

        $start = max(0, $start);

        return $start;

    }