Concrete5.7 external forms issue

altcontroller_contact_form.php

<?php

/**
 * Alternative controller file - this one is actually loaded, though I'm forced to put it somewhere silly.
 * (installed at concrete/blocks/external_form/form/controller/contact_form.php)
 */

namespace Concrete\Block\ExternalForm\Form\Controller;

class ContactForm extends \Concrete\Core\Controller\AbstractController
{
    /**
     * Sends the email.
     *
     * @return boolean
     */
    public function action_send()
    {
        die('Loaded controller successfully'); // This works
    }

    /**
     * Displays the form.
     */
    public function view()
    {
    }
}

contact_form.php

<?php

/**
 * View file for the form
 * (as installed at application/blocks/external_form/form/contact_form.php, as sugggested when you add the block)
 */

defined('C5_EXECUTE') or die("Access Denied.");

?>

<?php if(isset($response)): ?>
    <div class="alert alert-info"><?php echo $response; ?></div>
<?php endif; ?>

<form method="post" action="<?php echo $view->action('send')?>">
    <input type="hidden" name="contact[subject]" id="contact_subject" value="" />

    <div class="field">
        <label for="contact_name"><?php echo t('Your name')?></label>
        <input type="text" name="contact[name]" id="contact_name" required="required" />
    </div>

    <div class="field">
        <label for="contact_email"><?php echo t('Your email address')?></label>
        <input type="email" name="contact[email]" id="contact_email" required="required" />
    </div>

    <div class="field">
        <label for="contact_message" class="label-block"><?php echo t('How can we help?')?></label>
        <textarea name="contact[message]" id="contact_message" required="required"></textarea>
    </div>

    <div class="field">
        <input type="submit" name="contact[submit]" id="contact_submit" value="Send email" class="btn btn-primary btn-l" />
    </div>
</form>

controller_contact_form.php

<?php

/**
 * Controller file for the form
 * (as installed at application/blocks/external_form/form/controller/contact_form.php, which seemed to be mirror the example)
 */

namespace Application\Block\ExternalForm\Form\Controller;

class ContactForm extends \Concrete\Core\Controller\AbstractController
{
    /**
     * Sends the email.
     *
     * @return boolean
     */
    public function action_send()
    {
        die('Loaded controller successfully'); // This never happens
    }

    /**
     * Displays the form.
     */
    public function view()
    {
    }
}