Pagination links missing for first link (1) and previous button? How to get pagination links to work?

Question

I'm trying to add pagination to my WordPress query using pagination_links() however I am getting no links returned for my page 1 links and previous link? Other links are adding the paged query string to the URL which then redirect you to /page/3/ for example. Unsure whether I need to update the query below to add these URL's instead of the query string?

Can anyone see what is wrong with the below and how I can get the pagination links to be correct?

Any advice and help would be appreciated.

Query & Pagination:

$posts_per_page = get_option('posts_per_page');
$paged = ( get_query_var( 'paged' ) ) ? absint( get_query_var( 'paged' ) ) : 1;

$args = array(
    'posts_per_page' => $posts_per_page,
    'post_type' => 'post',
    'paged' => $paged,
);

$articles = new WP_Query( $args ); 

$args = array(
    'base'               => '%_%',
    'format'             => '?paged=%#%',
    'current'            => max( 1, get_query_var('paged') ),
    'total'              => $wp_query->max_num_pages,
    'show_all'           => false,
    'end_size'           => 1,
    'mid_size'           => 1,
    'prev_next'          => true,
    'prev_text'          => '<span class="icon icon-arrow-left" aria-hidden="true"></span><span class="sr-only">Previous</span>',
    'next_text'          => '<span class="icon icon-arrow-right" aria-hidden="true"></span><span class="sr-only">Next</span>',
    'type'               => 'plain',
    'add_args'           => false,
    'add_fragment'       => '',
    'before_page_number' => '',
    'after_page_number'  => ''
);

echo paginate_links( $args );

Returned HTML:

<div class="pagination">
    <a class="prev page-numbers" href=""><span class="icon icon-arrow-left" aria-hidden="true"></span><span class="sr-only">Previous</span></a>
    <a class="page-numbers" href="">1</a>
    <span aria-current="page" class="page-numbers current">2</span>
    <a class="page-numbers" href="?paged=3">3</a>
    <a class="next page-numbers" href="?paged=3"><span class="icon icon-arrow-right" aria-hidden="true"></span><span class="sr-only">Next</span></a>            
</div>

Answer 1

I've updated the base in my $args which has resolved the issue.

'base' => preg_replace('/\?.*/', '/', get_pagenum_link()) . '%_%',