title: Font awesome unicode some icons not displaying
body: <p>I am using unicode as per cheetsheet:  <a href="https://fontawesome.com/v5/cheatsheet/free/solid" rel="nofollow noreferrer">https://fontawesome.com/v5/cheatsheet/free/solid</a></p>
  <p>I tried changing font-weight as per answer here but it hasnt helped: <a href="https://stackoverflow.com/questions/47712987/font-awesome-5-on-pseudo-elements">Font awesome 5 on pseudo elements</a></p>
  <p>Maybe the issue is in css I linked? I dont know where to get other css version if there is newer.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.icon {
    font-family: 'Font Awesome 5 Free', 'Font Awesome 5 Regular', 'Font Awesome 5 Brands', 'Arial';
    font-size: 18px;
    font-weight: 900;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;link href="https://use.fontawesome.com/releases/v5.7.2/css/all.css" rel="stylesheet" /&gt;
  &lt;div&gt;&lt;span class="icon brand"&gt;&amp;#xf834;&lt;/span&gt;airbnb&lt;/div&gt;
  &lt;div&gt;&lt;span class="icon"&gt;&amp;#xf42c;&lt;/span&gt;amazon-pay&lt;/div&gt;
  &lt;div&gt;&lt;span class="icon"&gt;&amp;#xe059;&lt;/span&gt;bacteria&lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>