why not load more working

i tried lot of time but not work with my custom theme. it is work fine with any default theme. but now my one work.

<div class="prot-area">
<div class="col-two">
  <ul>
    <?php if ( have_posts() ) : ?>
    <?php while ( have_posts() ) : the_post();  ?>
    <li class="figure"><a href="<?php echo get_the_post_thumbnail_url($post_id, 'full'); ?>" class="strip" title="<?php the_title(); ?>" data-strip-caption="<?php the_title(); ?>" data-strip-group="mygroup">
      <?php
		 if ( has_post_thumbnail() ) {
	the_post_thumbnail('medium');
}  ?></a>
    </li>
    <?php endwhile; ?>
  </ul>
</div>
<div class="clearfix"></div>
<div class="pagenav">
<div class="nav-previous alignleft"><?php next_posts_link( 'Older posts' ); ?></div>
<div class="nav-next alignright"><?php previous_posts_link( 'Newer posts' ); ?></div>
</div>
<?php else : ?>
<p><?php _e('Sorry, no posts matched your criteria.'); ?></p>
<?php endif; ?>
</div>

i set

Posts Selector = .prot-area
Post Selector = .figure
Navigation Selector = .pagenav
Next Selector = .nav-next

Post Selector i change many way. like li, li.figure, .prot-area li .. more way. but none is work.

any idea why. my everything updated

https://www.ads-software.com/plugins/malinky-ajax-pagination/