Taxonomy Terms parents not sent to the index

Hi,

I had added Taxonomy term parents for a field, please see the screenshot. I am using this module along with Search api solr module. On Tracking I found that the following line on line no 775 in search_api_solr/src/plugin/search_api/backend/SearchApiSolrBackend.php is not giving values for parent.

$values = $field->getValues();

So the value of field is coming blank and is not being sent to the index.
As an interim solution i am using the following code to send it to the index:

/*
 * Implements hook_search_api_solr_documents_alter().
 */
function hook_search_api_solr_documents_alter(array $documents, \Drupal\search_api\IndexInterface $index, array $items) {
  // Adds a "foo" field with value "bar" to all documents.
  if ($index->id() == 'general') {
    $storage = \Drupal::service('entity_type.manager')
      ->getStorage('taxonomy_term');
    foreach ($documents as $document) {
      if (isset($document->its_field_organization) && !empty($document->its_field_organization)) {
        $parents = $storage->loadAllParents($document->its_field_organization);
        if (!empty($parents)) {
          foreach ($parents as $parent) {
            $label = $parent->label();
            $text_value = new \Drupal\search_api\Plugin\search_api\data_type\value\TextValue($label);
            if (strlen($text_value->getText()) > 32766) {
              $label = new TextValue(Unicode::truncateBytes($text_value)->getText(), 32766);
            }
            $parent_name[] = strtolower($label);
          }
        }
        $document->setField('itm_field_organization_parents_tid', array_keys($parents));
        if (!empty($parent_name)) {
          $document->setField('tm_field_organization_parents_name', $parent_name);
        }
      }
    }
  }
}