Rank Math SEO - rank_math_html_sitemap shortcode lists HTML sitemap in all languages

Overview of the issue

The rank_math_html_sitemap shortcode provided by the Rank Math SEO plugin is displaying an HTML sitemap that includes pages from all languages, instead of displaying content only in the current language.

Workaround

Please, make sure of having a full backup of your site before proceeding.

• Open …/wp-content/plugins/seo-by-rank-math/includes/modules/sitemap/html-sitemap/class-posts.php file.
• Look for line 88.
• Change:

  		$sql       = "
  			SELECT l.ID, post_title, post_name, post_parent, post_date, post_type, l.post_modified
  			FROM (
  				SELECT DISTINCT p.ID, p.post_modified FROM {$wpdb->posts} as p
  				LEFT JOIN {$wpdb->postmeta} AS pm ON ( p.ID = pm.post_id AND pm.meta_key = 'rank_math_robots' )
  				WHERE (
  					( pm.meta_key = 'rank_math_robots' AND pm.meta_value NOT LIKE '%noindex%' ) OR
  					pm.post_id IS NULL
  				)
  				AND p.post_type IN ( '" . $post_type . "' ) AND p.post_status IN ( '" . join( "', '", esc_sql( $statuses ) ) . "' )
  				ORDER BY p.post_modified DESC
  			)
  			o JOIN {$wpdb->posts} l ON l.ID = o.ID " . $get_child . " ORDER BY " . $sort['field'] . " " . $sort['order']; // phpcs:ignore
  		return $wpdb->get_results( $wpdb->prepare( $sql ) ); // phpcs:ignore
  

• For:

  		$current_language = apply_filters( 'wpml_current_language', NULL );				
  		$sql = "
  		SELECT l.ID, post_title, post_name, post_parent, post_date, post_type, l.post_modified
  		FROM (
  			SELECT DISTINCT p.ID, p.post_modified FROM {$wpdb->posts} as p
  			LEFT JOIN {$wpdb->postmeta} AS pm ON ( p.ID = pm.post_id AND pm.meta_key = 'rank_math_robots' )
  			INNER JOIN {$wpdb->prefix}icl_translations AS icl ON ( p.ID = icl.element_id AND icl.language_code = %s AND icl.element_type LIKE 'post_%' )
  			WHERE (
  				( pm.meta_key = 'rank_math_robots' AND pm.meta_value NOT LIKE '%noindex%' ) OR
  				pm.post_id IS NULL
  			)
  			AND p.post_type IN ( %s ) AND p.post_status IN ( '" . join( "', '", esc_sql( $statuses ) ) . "' )
  			ORDER BY p.post_modified DESC
  		) o
  		JOIN {$wpdb->posts} l ON l.ID = o.ID " . $get_child . " ORDER BY " . $sort['field'] . " " . $sort['order']; // phpcs:ignore
  		$sql = $wpdb->prepare($sql, $current_language, $post_type);
  		return $wpdb->get_results( $sql ); // phpcs:ignore
  

Keep in mind that may need to reset your sitemaps. You can do that going to Rank Math SEO > Sitemaps settings, modifying a setting and changing it again.