Display relationship posts (ACF) after post content

Hi,

Using GP elements, I am trying to display related posts (using ACF relationship field) below a single post.

In my element (before_footer), I've used a similar code as the one mentioned in ACF ressources (https://www.advancedcustomfields.com/resources/relationship/) :

<?php 

$posts = get_field('relationship_field_name');

if( $posts ): ?>
    <ul>
    <?php foreach( $posts as $post): // variable must be called $post (IMPORTANT) ?>
        <?php setup_postdata($post); ?>
        <li>
            <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
            <span>Custom field from $post: <?php the_field('author'); ?></span>
        </li>
    <?php endforeach; ?>
    </ul>
    <?php wp_reset_postdata(); // IMPORTANT - reset the $post object so the rest of the page works correctly ?>
<?php endif; ?>

However, it doesn't work, it displays data of my current post...

Should I add a wp_reset_postdata(); somewhere before ?

Thanks !