Pagination error WordPress multiple loop

I would do something like this:

<?php

    //Protect against arbitrary paged values
    $paged = ( get_query_var( 'paged' ) ) ? absint( get_query_var( 'paged' ) ) : 1;

    $args = array(
        'posts_per_page' => 6,
        'category_name' => 'case-study',
        'paged' => $paged,
        'show_all'     => False,
        'prev_next'    => True

    );

    $the_query = new WP_Query( $args );
?>


<?php if ( have_posts() ) : while ( $the_query->have_posts() ) : $the_query->the_post(); ?>

//Insert your data feed here - links / images / text etc etc

 <?php endwhile; ?>

Pagination code below:

<?php

    $big = 999999999; // need an unlikely integer

    echo paginate_links( array(
        'base' => str_replace( $big, '%#%', esc_url( get_pagenum_link( $big ) ) ),
        'format' => '?paged=%#%',
        'prev_next' => 'true',
        'type' => 'list',
        'link_before' => '',
        'link_after'  => '',
        'prev_text'    => __('< FIRST'),
        'next_text'    => __('LAST >'),
        'show_all' => 'true',
        'current' => max( 1, get_query_var('paged') ),
        'total' => $the_query->max_num_pages
    ) );

 ?>

 <?php endif; ?>

Hope this helps 🙂