Pagination appends search query

I have created a custom search form. That works perfectly.

I have added pagination. That also works (almost) perfectly.

Now if I have the following search query/url
https://domain.com/?s=&ssd=1&spid=home&sex%5B%5D=4

Then the pagination link for the second page is
https://domain.com/page/2/?s&ssd=1&sex%5B0%5D=4#038;ssd=1&sex%5B0%5D=4

This part gets added: #038;ssd=1&sex%5B0%5D=4
But I have no clue as to why.

This is my pagination function:

function get_paging() {
    global $wp_query;

    if ( $wp_query->max_num_pages < 2 ) {
        return false;
    }

    $big  = 999999999; 
    $args = array(
        'base'      => str_replace( $big, '%#%', esc_url( get_pagenum_link( $big ) ) ),
        'format'    => '/page/%#%',
        'total'     => $wp_query->max_num_pages,
        'current'   => max( 1, get_query_var( 'paged' ) ),
        'show_all'  => false,
        'end_size'  => 3,
        'mid_size'  => 2,
        'prev_next' => true,
        'prev_text' => __( '&laquo; Previous', 'sexdates' ),
        'next_text' => __( 'Next &raquo;', 'sexdates' ),
        'type'      => 'list',
    );

    return sprintf( '<div class="paginator">%s</div>', paginate_links( $args ) );
}