tinymce does not work inside magnific popup

I am trying to use the Advanced Custom Fields acf_form() function inside of an INLINE type Magnific Popup to edit and create posts on a WordPress site. It’s a work in progress; here’s the link. You can log in with username test and password ukQfQ7zx7akPXH.

The WordPress content editor works, it’s just that I’m not able to click inside the “Visual” tab, which kind of defeats the purpose of a WYSIWYG.

I’ve made sure that each of the ACF forms has a unique id attribute. So, I’m guessing the problem is some sort of conflict with TinyMCE and Magnific Popup. However, no console errors are appearing in Chrome.

Has anyone encountered anything like this before?

UPDATE

Here’s the new code:

function cb_new_post_popup() { ?>
  <div id="new-post-popup"
       class="update-popup mfp-hide">
    <h3>New Post</h3>
    <?php
      $current_user = wp_get_current_user();
      $args = array('fields' => array('field_54134c496ff9d', 'field_541877c6025b3'),
                    'form_attributes' => array('id' => 'acf-form-new_post'),
                    'post_title' => true,
                    'post_content' => true,
                    'post_id' => 'new_post',
                    'new_post' => array('post_status' => 'publish'),
                    'return' => '%post_url%');
      acf_form($args);
    ?>
    <script>
    jQuery(function($) {
      acf.do_action('append', $('#new-post-popup'));
    });
    </script>
  </div>
<?php }

SECOND UPDATE

I’ve also tried adding this to the magnificPopup function in the JS:

callbacks: {
  open: function() {
    console.log('Popup is opened');
    acf.do_action('append', $(this));
  },
  close: function() {
    tinymce.activeEditor.save();
  }
  // e.t.c.
}