title: Wordpress 5.2 YouTube video auto-embed in posts is not working
body: <p>In my personal Wordpress blog (5.2), the auto-embed for videos does not work. The editor shows a spinner (very briefly), but then it shows the link to the video in the backend and the URL in plain text in the frontend instead.</p>
  
  <p>I've tried changing the post in different Browsers (all failed), I tried different videos - some from vimeo (none works). When I use the iframe embed-code provided by YouTube in the HTML-editor for the post the exact same video works fine in the same post.</p>
  
  <p>I've disabled all plugins and switched to the original theme, but that did not help, the auto-embed still does not work.</p>
  
  <p>It seems to know its supposed to create an embed element (judged by the code it generates for the frontend), but fails to do so apparently:</p>
  
  <pre><code>&lt;div&gt;
  &lt;!-- wp:core-embed/youtube {"url":"https://www.youtube.com/watch?v=ioZX_pJz-Cc","type":"video","providerNameSlug":"youtube","className":""} --&gt;
  &lt;figure class="wp-block-embed-youtube wp-block-embed is-type-video is-provider-youtube"&gt;
  &lt;div class="wp-block-embed__wrapper"&gt;https://www.youtube.com/watch?v=ioZX_pJz-Cc&lt;/div&gt;
  &lt;/figure&gt;
  &lt;!-- /wp:core-embed/youtube --&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I have no idea what to try next, and it's driving me nuts, so help would be highly appreciated.</p>
  
  <p>Thanks in advance and all the best,
  Lucas</p>