Resetting a Query using wp_reset_query() or wp_reset_postdata() does not work

I am using ACF as related posts. I have the following code.

?php $post_objects = get_field('repeater_related_items');
if( $post_objects ): ?
    ul
    ?php foreach( $post_objects as $post): // variable must be called $post (IMPORTANT) ?
        ?php setup_postdata($post); ?
        li
            a href="?php the_permalink(); ?"?php the_title(); ?/a
            span?php the_field('repeater_related_items'); ?/span
        /li
    ?php endforeach;?
    /ul
?php wp_reset_postdata(); ?  
?php endif;?
?php if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar('Main Sidebar') ) : endif; ?

The problem is that when I add this to sidebar other widget doesn't work.