Please advise....

I create filter taxonomy using this tutorial: https://www.bobz.co/blog/demo-filter-wordpress-posts-custom-taxonomy-term-ajax/

It is echoing all my codes but when I click to certain tag it stop showing me images only.

I am using ACF Gallery code for images in template.

<?php 
$images = get_field('gallery');
if( $images ): ?>
    <ul>
        <?php foreach( $images as $image ): ?>
            <li>
                <a href="<?php echo $image['url']; ?>">
                     <img src="<?php echo $image['sizes']['thumbnail']; ?>" alt="<?php echo $image['alt']; ?>" />
                </a>
                <p><?php echo $image['caption']; ?></p>
            </li>
        <?php endforeach; ?>
    </ul>
<?php endif; ?>

I check ajax filter post file and try to edit code but still fails to do so can you please help me out with it.

I want gallery to be display with certain posts when I click on "TAGS"

    $output  = '<h2><a href="'.get_permalink().'">'. get_the_title() . '</a></h2>';
    $output .= get_the_excerpt();


    $result = 'success';

  endwhile; else:
    $output = '<h2>No posts found</h2>';
    $result = 'fail';
  endif;