Flash Direct not working on Phalcon 3.0?

Phalcon 3.0; PHP 5.6 (nginx + fpm); OS: Debian 7.6

Does Flash Direct works correctly? I can't get it to output.

services.php (flash stuff):

use Phalcon\Flash\Direct as Flash;
use Phalcon\Flash\Session as FlashSession;

/**
 * Register the flash service with the Twitter Bootstrap classes
 */
$di->setShared('flash', function () {
    return new Flash(
        [
            'error'   => 'alert alert-danger',
            'success' => 'alert alert-success',
            'notice'  => 'alert alert-info',
            'warning' => 'alert alert-warning',
        ]
    );
});

/**
 * Register the session flash service with the Twitter Bootstrap classes
 */
$di->setShared('flashSession', function () {
    return new FlashSession(
        [
            'error'   => 'alert alert-danger',
            'success' => 'alert alert-success',
            'notice'  => 'alert alert-info',
            'warning' => 'alert alert-warning',
        ]
    );
});

Part of the controller that puts message(s) into flash service:

            // Form is INVALID, forward to edit form, data preserved
            if(!$form->isValid($this->request->getPost())) {
                foreach($form->getMessages() as $message) {
                    $this->flash->error($message);
                }
                //var_dump($this->flash->output());die;       // THIS OUTPUTS THE MESSAGE
                $this->dispatcher->forward(
                    [
                        'action' => 'edit',
                        'params' => [0 => $planId],
                    ]
                );

                return true;    
            }

View volt file (actually a template setTemplateAfter("general")), general.volt:

        {{ flash.output() }}            // THIS DOES'T SHOW ANYTHING
        {{ flashSession.output() }}     //THIS SHOWS WHEN I USE $this->flashSession

Phalcon 3.0.0 Use FlashDirect https://docs.phalconphp.com/en/latest/reference/flash.html

<?php

use Phalcon\Flash\Direct as FlashDirect;

// Register the flash service with custom CSS classes
$di->set('flash', function () {
    $flash = new FlashDirect(
        array(
            'error'   => 'alert alert-danger',
            'success' => 'alert alert-success',
            'notice'  => 'alert alert-info',
            'warning' => 'alert alert-warning'
        )
    );

    return $flash;
});