#ajax doesn't seem to work inside drupal_render()

Below is the form fragment that I am having trouble with:

 
  // search filters
  $form['search_widget']['filters'] = array(
    '#theme' => 'qapi_search_filters_display',
    '#tree' => true,
  );
  
  // filter storage element
  $form['search_widget']['filters']['filter_json'] = array(
    '#type' => 'hidden',
    '#default_value' => drupal_json_encode($saved_filters),
    '#attributes' => array(
      'id' => 'filter-json'
    ),
  );
  
  if (isset($form_state['storage']['filters'])){
    foreach ($form_state['storage']['filters'] as $n => $filter){
      $form['search_widget']['filters']['rows'][$n] = array(
        '#type' => 'checkbox',
        '#attributes' => array(
          'class' => array('qapi-search-widget-filter-cb'),
          'id' => 'filter-' . $n,
        ),
        '#filter' => $filter,
        '#default_value' => 1,
        '#ajax' => array(
          'callback' => 'qapi_search_filters_cb_handler',
          'event' => 'change',
          'progress' => array(
            'type' => ''
          )            
        )
      );
    }
  }
  

In my theme_qapi_search_filters_display, I am running drupal_render on the $form['search_widget']['filters']['rows'][$n] elements, but they are not getting processed with the #ajax behaviors that I need.

Any ideas?