Page heading not showing in App Home with Polaris web compo

Hi, I was following the example in Page and I can’t get the page heading to display when the Polaris web component is shown in the app home.

Here is the html. You can also see a hosted version on Polaris Heading Demo

<!DOCTYPE html>
<html>
  <head>
    <title>Polaris Heading Demo</title>
    <script src="https://cdn.shopify.com/shopifycloud/app-bridge.js"></script>
    <script src="https://cdn.shopify.com/shopifycloud/polaris.js"></script>
  </head>

  <body>
    <s-page heading="Products">
      <s-section>
        <s-text>Hello World</s-text>
      </s-section>
    </s-page>
  </body>

</html>

We see the header when loading the page directly.

When I show it on app home, the header does not show.

I’m using HTML directly with the polaris and app-bridge scripts. Am I doing something wrong?