old url not redirecting to new url

Hi @mygayflatmate,

As far as I can see, the original listing permalinks were different, and you have changed them to “for-rent/LISTING ID” format. Only the original URLs are redirected to custom permalinks in the free version of the plugin. In the article below, you may learn more about native/initial URIs and canonical redirects.
https://permalinkmanager.pro/docs/plugin-settings/canonical-redirects/#4-how-does-canonical-redirect-affects-custom-permalinks

All URL modifications are not kept anywhere as extra redirects. This functionality is available only in Pro version:
https://permalinkmanager.pro/docs/plugin-settings/old-custom-permalinks-redirect/

Because your URLs end in post IDs, you may use your own fallback function to force a redirect if no post is detected but the ID extracted from the URL is used by post.

function pm_redirect_post_uris_from_404() {
	global $wp, $wpdb;

	if(is_404()) {
		$slug = basename($wp->request);

		// Check if the slug is numeric ID
		if(is_numeric($slug)) {
			$element = $wpdb->get_row($wpdb->prepare("
				SELECT * FROM {$wpdb->posts}
				WHERE ID = %d
				AND post_status = 'publish'
				",
				$slug
			));

			if(!empty($element->ID)) {
				$url = get_permalink($element->ID);

				wp_safe_redirect($url, 301);
				exit();
			}
		}
	}
}
add_action('template_redirect', 'pm_redirect_post_uris_from_404', 1);