Conflict with shortcode

Simple lightbox breaks when used on the same page with the following shortcode:

Do you know why? The shortcode itself works fine, and so does everything else on the page. I see no errors in the console. But Simple Lightbox is not adding the data attributes to the gallery links when this shortcode is present on the page.

function staffshortcode( $atts ) {
 
    extract(shortcode_atts(array('num' => '-1','category' =>''), $atts));
				
    $staffquery = new WP_Query( array(
      'post_status' => 'publish',
	  'post_type' => 'staff',
	  'orderby' => 'menu_order',
	  'order' => 'ASC',	
	  'posts_per_page' => -1,
	  'tax_query' => array(
		array(
			'taxonomy' => 'department',
			'field'    => 'slug',
			'terms'    => $category
		),
	     ),
	));
   
   // the loop
    if ( $staffquery->have_posts() ) : 
	while ( $staffquery->have_posts() ) : $staffquery->the_post(); 
   
          $temp_title = get_the_title($post->ID);
	  $temp_excerpt = get_the_excerpt($post->ID);
	  $temp_thumb = get_the_post_thumbnail($post->ID,'resident');
  
          $output .= '<div class="row"><div class="col-sm-4">'.$temp_thumb.'</div>
            <div class="col-sm-8"><h3>'.$temptitle.'</h3>'.$temp_excerpt.'</div></div><hr />';
          
	endwhile; wp_reset_query(); endif;
	
   return $output;
   
}
add_shortcode("staff", "staffshortcode");