setChangedTime() are not working at all

function mymodule_cron() {
  $query = \Drupal::entityQuery('webform_submission')
    ->condition('webform_id', 'mywebform')
    ->sort('created', 'ASC')
    ->accessCheck(FALSE);
  $result = $query->execute();
  $storage = \Drupal::entityTypeManager()->getStorage('webform_submission');
  $submissions = $storage->loadMultiple($result);
  
  foreach ($submissions as $submission) {
    $user_id = $submission->getOwnerId();
    $user = \Drupal\user\Entity\User::load($user_id);
    
    // Récupération des champs utilisateurs.
    $sp = $user->field_situation_p->value;
    $sf = $user->field_situation_f->value;
    $cua = $user->field_cua->target_id;
    
    if (!empty($sp)) {
      $submission->set('elements.sp', $sp);
    }
    
    if (!empty($sf)) {
      $submission->set('elements.sf', $sf);
    }
    
    if (!empty($cua)) {
      $submission->set('elements.cua', $cua);
    }
    
    $submission->save();
  }
}

Try this if it's work.

Hello @dharmeshbarot,

Thanks for the answer but the changed date is updated by the current timestamp.

Whereas if my changed date is 03/24/2023 - 6:00 am, I want after the cron run that the date remains 03/24/2023 - 6:00 am, not the date where the cron puts update on the webform submission..

function mymodule_cron() {
  $query = \Drupal::entityQuery('webform_submission')
    ->condition('webform_id', 'mywebform')
    ->sort('created', 'ASC')
    ->accessCheck(FALSE);
  $result = $query->execute();
  $storage = \Drupal::entityTypeManager()->getStorage('webform_submission');
  $submissions = $storage->loadMultiple($result);
  
  foreach ($submissions as $submission) {
    $user_id = $submission->getOwnerId();
    $user = \Drupal\user\Entity\User::load($user_id);
    
    // Récupération des champs utilisateurs.
    $sp = $user->field_situation_p->value;
    $sf = $user->field_situation_f->value;
    $cua = $user->field_cua->target_id;

    // Store the original changed timestamp before modifying the submission data.
    $originalChangedTime = $submission->getChangedTime();

    if (!empty($sp)) {
      $submission->setElementData('sp', $sp);
    }
    
    if (!empty($sf)) {
      $submission->setElementData('sf', $sf);
    }
    if (!empty($cua)) {
      $submission->setElementData('cua', $cua);
    }

    // Restore the original changed timestamp before saving the submission.
    $submission->setChangedTime($originalChangedTime);
    $submission->save();
  }
}

Thank you @dharmeshbarot, I'm waiting for your answer

function mymodule_cron() {
  $query = \Drupal::entityQuery('webform_submission')
    ->condition('webform_id', 'mywebform')
    ->sort('created', 'ASC')
    ->accessCheck(FALSE);
  $result = $query->execute();
  $storage = \Drupal::entityTypeManager()->getStorage('webform_submission');
  $submissions = $storage->loadMultiple($result);
  
  foreach ($submissions as $submission) {
    $user_id = $submission->getOwnerId();
    $user = \Drupal\user\Entity\User::load($user_id);
    
    // Récupération des champs utilisateurs.
    $sp = $user->field_situation_p->value;
    $sf = $user->field_situation_f->value;
    $cua = $user->field_cua->target_id;

    // Load the full submission entity object to be able to modify its fields.
    $full_submission = $storage->load($submission->id());

    if (!empty($sp)) {
      $full_submission->setElementData('sp', $sp);
    }
    
    if (!empty($sf)) {
      $full_submission->setElementData('sf', $sf);
    }
    if (!empty($cua)) {
      $full_submission->setElementData('cua', $cua);
    }

    // Preserve the original changed timestamp by explicitly setting it again.
    $full_submission->set('changed', $submission->getChangedTime());

    // Call save() to persist the changes to the submission entity.
    $full_submission->save();
  }
}

Thanks for the answer, but it still doesn't work, I think the ->save() method will always overwrite the update date.