executors.jelly - I cant see progress bar

[justine....@gmail.com]

hello
In my plugin I'm creating new suppage like http://(...)/jenkins/my-page. I want to present there, among other things, list of nodes in slightly changed form.
By now I copied file executors.jelly (I will be changing it later) to my project and in index.jelly page I put code:

<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler"
    xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson"
    xmlns:f="/lib/form" xmlns:i="jelly:fmt" xmlns:u="/util">
    <td><st:include page="executors.jelly" /></td>
<l:ajax>

<td><st:include page="executors.jelly" /></td>

</l:ajax>
</j:jelly>

I see running build, it's name and I can get URL adress, but I don't see its progress bar. Does anyone have an idea why? Please help me.
p.s. If "include page" is outside ajax I see "Unknown Task" instead of build name/link