I’ve got a page where I only want to display one post per page with pagination at the bottom to go to the next/ previous post.
This is my code:

  <?php $paged = ( get_query_var( 'paged' ) ) ? get_query_var( 'paged' ) : '1';
$args = array (
    'nopaging'               => false,
    'paged'                  => $paged,
    'posts_per_page'         => '1',
    'post_type'              => 'post',
    'category_name'          => 'enforcement',
);
?>
    <?php 
     $wp_query = new WP_Query($args);
    ?>

    <?php if ( $wp_query->have_posts() ) : ?>
    <?php while ( $wp_query->have_posts() ) : the_post(); ?>   
<!--<div class="case-studies-text-banner">
   <img src="http://www.mariadev.co.uk/wp-content/uploads/2017/05/case-study-layer.png"/>
    <div class="case-study-title"><?php the_title(); ?></div>
    <div class="case-study-pdf"><?php if (function_exists("wpptopdfenh_display_icon")) echo wpptopdfenh_display_icon();?></div>
    </div>-->

    <?php the_content(); ?>

    <?php endwhile; ?>

<?php next_posts_link( 'Older Entries »', $query->max_num_pages ); ?>


     <?php wp_reset_postdata(); ?>
    <?php else : ?>
    <p><?php __('No News'); ?></p>
    <?php endif; ?>

It does only show 1 post on the first page but when clicking on older posts and moving to this url www.testing./?cat=8&paged=2 no posts show even though there are 3 posts in this category.
Any ideas what I’m doing wrong?