Including customized question var to a single put up with out redirecting to its root slug

I’ve created a put up to posts relationship utilizing ACF. On the one web page of considered one of my CPTs I wish to add a prettified ID to the top of the slug to load totally different values on the web page (/my-archive/my-single-post/ID) and have that ID saved to a question variable known as custom_id. I additionally are not looking for the web page to redirect to the unique slug (/my-archive/my-single-post/).

I’ve managed to do the next:

add_action( 'init',  'add_custom_id_rewrite_rules' );
perform add_custom_id_rewrite_rules() {
    add_rewrite_rule( '^my-archive/([^/]*)/([0-9]+)?$', 'index.php?post_type=my_post_type&pagename=$matches[1]&custom_id=$matches[2]', 'high' );
}

add_filter( 'query_vars', 'add_custom_id_query_vars' );
perform add_custom_id_query_vars( $query_vars ) {
    $query_vars[] = 'custom_id';
    return $query_vars;
}

From all over the place I learn, this could work. I’ve put in the Rewrite Rule Analyzer and it detects my custom_id appropriately. Nonetheless, regardless of it being thought of appropriate I nonetheless get redirected to /my-archive/my-single-post/.

I would like the question to nonetheless pull the_title() from that single put up I simply need to have the ability to question custom_id to vary issues on the web page.

Ideas?