Some address not loading / displaying

Hi all,

I am working to improve a website and replace Google Map system.
So I am trying to display the map related directly to addresses, in my file PHP, as seen below :

<?php
	        // on fait de $post une variable globale
			global $post;

			// on stocke la variable dans un nom de variable inutilisé
			$book_post_ID = $post->ID;
			$rue_post_ID = get_post_meta( $book_post_ID, 'cp_street', true );
			$codepostal_post_ID = get_post_meta( $book_post_ID, 'cp_zipcode', true );
			$ville_post_ID = get_post_meta( $book_post_ID, 'cp_city', true );
			$pays_post_ID = get_post_meta( $post->ID, 'cp_country', true );

			// enfin, on fait appel au shortcode de l'extension "Leaflet Map"
			echo do_shortcode("[leaflet-map address='". $rue_post_ID ." ". $codepostal_post_ID ." ". $ville_post_ID ." ". $pays_post_ID ."' zoom=17]");
		?>

Most of the time, it works, but some address will not load, and default coordinates appear instead.

How can I correct this, and make it work pemanently? Should I try another free system / API / anything else, and how ?
Thanks.