Custom Query Not Paginating

You need to set paged or an offset in your query, otherwise you’re always fetching the same 48 posts.

$page = (get_query_var('page')) ? get_query_var('page') : 1;
$args = array(
 'paged' => $page,
 'posts_per_page' => '48',
 'cat' => '4',
 'meta_query' => array(
     array(
        'key' => 'Country',
        'value' => $country_search_array,
        'compare' => 'IN'
     )
  )
);
$gallery_query = new WP_Query( $args );?>