function remove_all_tags( $changes, $user_id ) {

    if ( did_action( 'user_register' ) ) {
        return;
    }

    $tags = wpf_get_tags( $user_id );
    wp_fusion()->user->remove_tags( $tags, $user_id );

}

add_action( 'um_before_update_profile', 'remove_all_tags', 10, 2 );