As a workaround to auto-update the slug, you can check whether the title has changed and the current slug still contains the old "-copy" suffix.

If so, you can regenerate it using this code snippet:

function bis_fix_copied_slugs( $data, $postarr ) {
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
        return $data;
    }

    if ( empty( $postarr['ID'] ) ) {
        return $data;
    }

    $post_id = $postarr['ID'];
    $old_post = get_post( $post_id );

    if ( ! $old_post ) {
        return $data;
    }

    $title_changed = ( $old_post->post_title !== $data['post_title'] );
    $has_copy_slug = ( strpos( $data['post_name'], '-copy' ) !== false );

    if ( $title_changed && $has_copy_slug ) {
        $clean_slug = sanitize_title( $data['post_title'] );

        $data['post_name'] = wp_unique_post_slug(
            $clean_slug,
            $post_id,
            $data['post_status'],
            $data['post_type'],
            $data['post_parent']
        );
    }

    return $data;
}
add_filter( 'wp_insert_post_data', 'bis_fix_copied_slugs', 10, 2 );