Why don't generated HTML blocks in JS want to trigger popup show events?

Question

JavaScript

The blocks in the blue frames have Popup events, since they are written in the html document itself, and the blocks in the red frames were loaded using an AJAX request. Why don't these blocks have this event?

If I use the JQuery script leanModal , the block window appears when you click on the link with the parameter, and here is the hidden block
<a href="#hidden_block" rel="leanModal">

<div id="hidden_block" class="lean_overlay">
   <p>Я скрытый блок, который не хочет показываться :)</p>
</div>

Thanks in advance!

Answer 1

Added elements not responding to mouseenter?
Hang event handlers on ancestors.

<ul>
  <li></li>
<ul>

$("ul").on("click", "li", function(){ ... });