Webform handler to manage number of places available

I want to manage a webform to automatically close it if number of people reached, or to invalid submission if not enough places are available.

I have use this : Close a webform when total seats reach a maximum to try to make a handler

here is my code :

<?php
namespace Drupal\webform_reservations\Plugin\WebformHandler;

use Drupal\Core\Form\FormStateInterface;
use Drupal\webform\Plugin\WebformHandlerBase;
use Drupal\webform\webformSubmissionInterface;

/**
 * Form submission handler.
 *
 * @WebformHandler(
 * id = "webform_reservations_handler",
 * label = @Translation("Reservations Handler"),
 * category = @Translation("Form Handler"),
 * description = @Translation("Manage maximum reservations by submission. Be Carfull some parameters are needed for working !"),
 * cardinality = \Drupal\webform\Plugin\WebformHandlerInterface::CARDINALITY_SINGLE,
 * results = \Drupal\webform\Plugin\WebformHandlerInterface::RESULTS_PROCESSED,
 * )
 */

class ReservationHandler extends WebformHandlerBase {

  /**
   * {@inheritdoc}
   */

  public function submitForm(array &$form, FormStateInterface $form_state, WebformSubmissionInterface $webform_submission) {
    $webform = $webform_submission->getWebform();
    $formid = $webform->id();
    $event_max_people= $webform_submission->getElementData('event_max_people');

//query the db for all submissions of current webform submission
    $query = \Drupal::entityQuery('webform_submission');
    $query->condition('webform_id', $formid);
    $result = $query->execute();

//load all the submissions from the results
    $storage = \Drupal::entityTypeManager()->getStorage('webform_submission');
    $submissions = $storage->loadMultiple($result);
    $submission_data = array();

    foreach ($submissions as $submission) {
      $submission_data[] = $submission->getData();
    }
    $current_reserved = 0;
//add up all the values in the 'number_of_people' field of each submission and save it to a variable.
    for ($i = 0; $i < count($submission_data); $i++){
      $current_reserved += $submission_data[$i]['number_of_people'];
    }

    if ($event_max_people <= $current_reserved) {
      // normally impossible state because the form automatically close when number of people is reached.
      // TODO : change the status of the form and not add this submission
      $webform->setStatus(WebformInterface::STATUS_CLOSED);
      $webform->save();
      $log_message = "The form is full, so it's now closed, but normally it should already have been closed!?";

    } elseif ( $event_max_people == $current_reserved + $webform_submission->getElementData('number_of_people')) {
      // just the number of people to close the registrations
      // TODO : So change form status to close and add the submission.
      $webform->setStatus(false);
      $webform->save();
      $log_message = "The form is full, so it's now closed. From " .$current_reserved. "/" .$event_max_people. " to ".($current_reserved+$webform_submission->getElementData('number_of_people')). "/" .$event_max_people . ".";

    } elseif ($event_max_people < $current_reserved + $webform_submission->getElementData('nombre_de_personnes')) {
      // Not enough places
      // TODO : No submission and go back to the form with a message
      $log_message = "There are only " . ($event_max_people-$current_reserved) ." places left so not enough for your ".$webform_submission->getElementData('number_of_people') ." requested places !";

    } else {
      // everything is ok, so nothing to do, only a message in the log
      $log_message = "The form had " .$current_reserved. "/" .$event_max_people. " people, and now, it has : ".($current_reserved+$webform_submission->getElementData('number_of_people')). "/" .$event_max_people . " people.";
    }

//log the output to the drupal logger, to indicate if the webform is still open or closed after each submission.
    \Drupal::logger('webform_reservations')->info($log_message);
  }
}

I have a problem how to change the status ? I have try :

    $webform->setStatus(false);
    $webform->save();
    
    //or
    
    $webform->setStatus(WebformInterface::STATUS_CLOSED);
    $webform->save();

    //but each time I have the error : 

    Drupal\webform\WebformException : eventVoyage webform [event_voyage] has overridden settings and/or properties and can not be saved. dans Drupal\webform\Entity\Webform->preSave() (ligne 2296 de /var/www/html/web/modules/contrib/webform/src/Entity/Webform.php).