Arrows not showing on Custom Post Type

Ok, so the arrows only show up if I insert the images directly in the post content (entry content).

I use this code but it doesn’t help, do I have to edit every post to get the arrows there?

<?php
			the_content();

			wp_link_pages( array(
				'before'      => '<div class="page-links"><span class="page-links-title">' . __( 'Pages:', 'twentysixteen' ) . '</span>',
				'after'       => '</div>',
				'link_before' => '<span>',
				'link_after'  => '</span>',
				'pagelink'    => '<span class="screen-reader-text">' . __( 'Page', 'twentysixteen' ) . ' </span>%',
				'separator'   => '<span class="screen-reader-text"> </span>',
			) );

			if ( '' !== get_the_author_meta( 'description' ) ) {
				get_template_part( 'template-parts/biography' );
			}

$images =& get_children( array (
	'post_parent' => $post->ID,
	'post_type' => 'attachment',
	'post_mime_type' => 'image',
	'posts_per_page' => 25
));

	if ( empty($images) ) {
		

	} else {
		foreach ( $images as $attachment_id => $attachment ) {
			echo wp_get_attachment_link( $attachment_id, 'thumbnail' );

		}
	}
		?>

Hi Caroline,

The plugin is made to look for images inside the content area. I can’t test it on your environment, but if you add a class of “gallery” to the current “pics” div, it may work as you’d like.

It works ?? Thank you so much for your help!