Correct syntax to html php conversion

you are missing the three curly brackets in before wp_reset_postdata().

backup your code and replace with this.

<?php
$args = array('post_type' => 'menu', 'posts_per_page' => 5, 'post__in'  => $ids, 'post_status' => 'any', 'orderby' => 'post__in');

$query = new WP_Query( $args );
if ( $query->have_posts() ) {
    while ( $query->have_posts() ) {
        $query->the_post();
        if (is_page(538) ) {
            echo get_the_title();
            $levesek = get_field('levesek');
            $leves_adag = get_field('leves_adag');
            echo "<br>Levesek:<br>";
            if($levesek) {
                foreach ($levesek as $leves) {
                    setup_postdata($leves);
                        echo get_the_post_thumbnail( $leves->ID ) ."<br>";
                }
            }
        }
    }
}
wp_reset_postdata();
?>