title: IonicV4 Menu Component inside Split Pane not showing
body: <p>I'm trying to build an app with Ionic V4. I'm following Ionic Docs but It's a headache even for simplest things. </p>
  
  <p>I want to show a split pane with a side menu. The side menu is a component with this html:</p>
  
  <p><strong>menu.component.html</strong></p>
  
  <pre><code>&lt;ion-menu contentId="content1"&gt;
  &lt;ion-header&gt;
      &lt;ion-toolbar&gt;
          &lt;ion-title&gt;Menú&lt;/ion-title&gt;
      &lt;/ion-toolbar&gt;
  &lt;/ion-header&gt;
  </code></pre>
  
  <p></p>
  
  <p>In the other side</p>
  
  <p><strong>app.component.html</strong></p>
  
  <pre><code>&lt;ion-app&gt;
  &lt;ion-split-pane&gt;
      &lt;app-menu&gt;&lt;/app-menu&gt;
      &lt;ion-router-outlet id="content1" main&gt;&lt;/ion-router-outlet&gt;
  &lt;/ion-split-pane&gt;
  </code></pre>
  
  <p></p>
  
  <p>And I get a blank side menu like this</p>
  
  <p><a href="https://i.stack.imgur.com/1v57H.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1v57H.png" alt="enter image description here"></a></p>
  
  <p>But, if I paste the menu.component's HTML instance of  I see everything fine</p>
  
  <p><a href="https://i.stack.imgur.com/AX9k4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AX9k4.png" alt="enter image description here"></a></p>
  
  <p><strong>EDIT</strong>: I've forget to mention that I use Ionic 4 beta 17</p>