selectors doesn't work, what is wrong?

I’m developing my own theme and added Infinite Scroll plugin for loading my custom post type “reference”. Pagination is ok, if I click on “Older” can see loading. But result is “no additional posts” (and I have three more posts like that). I think it’s maybe because I have wrong selection in Settings. Here is what I have:

Content selector: .reference

Navigation selector: #nav

Next selector: #nav .older a

Item selector: .ref

Behavior: Manual Trigger

for this code:

<div class="container center reference">
  <?php
    $temp = $wp_query;
    $wp_query = null;
    $wp_query = new WP_Query();
    $wp_query->query('showposts=3&post_type=reference'.'&paged='.$paged); 

    while ($wp_query->have_posts()) : $wp_query->the_post();
  ?>

<div class="ref hidden" style="float:left; margin: 10px">
  <a>" rel="lightbox">
    <?php the_post_thumbnail( 'medium' );  ?>
  </a>
  <div style="display: none;">
    <div id="reference-<?php echo the_ID(); ?>">
      <?php the_title();  ?> <?php echo the_excerpt();?>

<?php the_post_thumbnail( 'medium' );  ?>
    </div>
  </div>
</div>
<?php endwhile; ?>

<nav id="nav">
  <div class="newer"><?php previous_posts_link('? Newer') ?></div>
  <div class="older"><?php next_posts_link('Older ?') ?></div>
</nav>
</div>

I tried change it, but still nothing works. My page is https://www.primawork.cz (it’s at the end of page with heading “Na?e reference”) and pagination without Infinite Scroll works well. Is it really just about wrong selector or have anyone some other experience?

https://www.ads-software.com/plugins/infinite-scroll/