title: jquery Form.submit handler not triggered
body: <p>trying to use <code>form.submit(event)</code> handler to send form data with ajax based on following example.
  <a href="https://stackoverflow.com/questions/1960240/jquery-ajax-submit-form">jQuery AJAX submit form</a></p>
  
  <p>But my Handler function does not seem to trigger at all, I have tried adding return false and various prevention of default behavior, but the form still get submitted to action file.</p>
  
  <p><strong>Javascript:</strong></p>
  
  <pre><code>$('#formWebUI').submit(function(e) {
  
          e.preventDefault();
          e.stopPropagation();
          e.stopImmediatePropagation();
  
          let form = $(this);
          let url = form.attr('action');
  
          $.ajax({
                 type: "POST",
                 url: url,
                 data: form.serialize(), // serializes the form's elements.
                 success: function(data)
                 {
                     ChangeLocation();
                 }
               });
          return false;
      });
  </code></pre>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;form id="formWebUI" class="form-inline pb-5" action="/php/form_WebUI.php" method="POST"&gt;
        &lt;div class="container"&gt;
          &lt;div class="row"&gt;
            &lt;div class="col-3 p-0"&gt;
              &lt;div class="form-group"&gt;
                &lt;input type="text" class="form-control w-100" id="alias" name="alias" placeholder="Alias"&gt;
              &lt;/div&gt;
            &lt;/div&gt;
            &lt;div class="col-7 px-1"&gt;
              &lt;div class="form-group"&gt;
                &lt;input type="text" class="form-control w-100" id="text" name="text" placeholder="Text"&gt;
              &lt;/div&gt;
            &lt;/div&gt;
            &lt;div class="col-2 p-0"&gt;
              &lt;input type="submit" class="btn btn-secondary w-100" id="formWebUI" value="Add"&gt;
            &lt;/div&gt;
          &lt;/div&gt;
        &lt;/div&gt;
      &lt;/form&gt;
  </code></pre>
  
  <p>I have also tried the button to be of element button instead of input. Type of the element was always submit never button.
  I have tried alerting in javascript, but it seems that the handler is never called no matter what I do. Would be thankful for any advice. </p>