This code will check database for all the post types and create the ones that are not registered using register_post_type() function

register-missing-post-types-wp.php

/*
* Register Missing Post Types
* Description: This code will check database for all the post types and create the ones that are not registered using register_post_type() function.
* Author: Abdul Awal Uzzal
* Author URI: https://abdulawal.com/
* License: GPLv2 or later
* License URI: http://www.gnu.org/licenses/gpl-2.0.html
*/
function tnc_register_unavailable_post_types(){
	global $wpdb;
	$posts_table = $wpdb->prefix.'posts';
	$get_types_from_db = $wpdb->get_results( "SELECT post_type FROM $posts_table", ARRAY_A);
	$db_post_types = array();
	foreach ( $get_types_from_db as $post_id => $post_type ) {
		$db_post_types[] = $post_type['post_type'];
	}
	$unique_db_post_types = array_unique($db_post_types);

	$registered_ptypes = get_post_types();
	$unavailable_post_types = array_diff($unique_db_post_types, $registered_ptypes);

	foreach ($unavailable_post_types as $key => $post_type_key) {
	    $args = array(
	      'public' => true,
	      'label'  => $post_type_key
	    );
		register_post_type( $post_type_key, $args);
	}
}
add_action( 'init', 'tnc_register_unavailable_post_types', 10 );