Custom slideshow on front page

Hi All!
I created a slideshow (gallery post format):

<div id="post-gallery-<?php the_ID(); ?>" class="orbit" role="region" aria-label="post-gallery-<?php the_ID(); ?>" data-orbit>
  <!-- Wrapper for slides -->
  <ul class="orbit-container" >
     <?php
     $i = 0;
     foreach( $attachments as $attachment ):
     $active = ( $i == 0 ? ' is-active': '' );
     ?>
     <li class="orbit-slide<?php echo $active; ?>">
        <img class="orbit-image" src="<?php echo wp_get_attachment_url($attachment->ID); ?>" />
     </li>
     <?php
         $i++;
         endforeach;
     ?>
  </ul><!--.orbit-container-->
</div><!--.orbit-->

Everything is working!

Now I want to display a slide show on the home page

<?php
	//Include gallery posts
	$args = array(
		'tax_query' => array(
			array(
				'taxonomy' => 'post_format',
				'field'    => 'slug',
				'terms'    => array( 'post-format-gallery' ),
			),				 
		),	  
	);
	$galleryPost = new WP_Query( $args );
		if ( $galleryPost->have_posts() ) :
			while ( $galleryPost->have_posts() ) : $galleryPost->the_post(); ?>
			<!--<pre><?php print_r($galleryPost); ?></pre>-->
			<div class="medium-4 columns">
				<div class="callout" data-equalizer-watch="galleryone">
				<?php
					the_title( '<h4 class="entry-title">', '</h4>' );
					the_content();
					the_meta();
				?>
				</div>
			</div>
			<?php endwhile;
		else :
		endif;
	wp_reset_postdata();
?>

It displays all the images (slideshow does not work).

If I use inside the loop
get_template_part( 'template-parts/post/content', 'gallery' );
, nothing is displayed

I need help, please