If you've added an element on a post to display some items and click the page numbers or load more button the same items may be loaded. This is because some servers do not accept the standard pagination URL structures on posts (it should be fine on pages). If this is the case activate the child theme and add the following to the functions.php file:

function ghostpool_custom_pagenum_link( $link ) {
    if ( is_single() ) { 
        return preg_replace( '~/page/(\d+)/?~', '?page=\1', $link );
    } else {
        return $link;
    } 
}
add_filter( 'get_pagenum_link', 'ghostpool_custom_pagenum_link' );