title: <p:blockUI> does not respond on <h:commandButton><f:ajax>
body: <p>I got a <code>&lt;h:commandButton</code> like: </p>
  
  <pre><code>&lt;h:commandButton id="login"
    actionListener="#{bean.login}" value="Login"
    styleClass="btn btn-primary btn-sm"&gt;
     &lt;f:ajax execute="@form" render="@form"/&gt;
  &lt;/h:commandButton&gt;
  </code></pre>
  
  <p>and a </p>
  
  <p><code>&lt;p:blockUI id="block" block=":form" trigger="login" /&gt;</code></p>
  
  <p>It is not working. The block is never shown up.</p>
  
  <p>It does work with a <code>&lt;p:commandButton&gt;</code>.</p>
  
  <p>How can I achieve it with a <code>&lt;h:commandbutton&gt;</code>. If that is not possible: Is there any workaround?</p>