title: Ionic 5 - ion-content doesn't have a visible overflow (cannot scroll)
body: <p>I am working on migrating an Ionic 3 / Angular 5 app to Ionic 5 / Angular 11 and I have a problem with the layout of the page: when I use <code>ion-header</code> and <code>ion-content</code>, the content of the page is not scrollable. Here is my code:</p>
  <pre><code>&lt;ion-header&gt;
      &lt;ion-toolbar&gt;
          &lt;ion-item lines=&quot;none&quot;&gt;
              &lt;ion-label&gt;
                  &lt;ion-title&gt;My title&lt;/ion-title&gt;
              &lt;/ion-label&gt;
          &lt;/ion-item&gt;
      &lt;/ion-toolbar&gt;
  &lt;/ion-header&gt;
  
  &lt;ion-content&gt;
      &lt;!-- A lot of content here --&gt;
      &lt;!-- This is not scrollable --&gt;
  &lt;/ion-content&gt;
  </code></pre>
  <p>By comparing the new layout with what I have in Ionic 3, while in Ionic 3 the header and the content have an <code>absolute</code> position with a top padding/offset (all these injected by Ionic), in Ionic 5 the position of the content is <code>relative</code> without any top padding. I am not sure if this is the real problem or what am I doing wrong, maybe there is something else I need to set.
  Is there a setting I can use for Ionic 5 so the problem disappears? Please advise. Thanks!</p>