Programmatically updating a Webform submission with a file element doesn't remove the attached files

Question

I am using Drupal 9.3 and Webform 6.1.7.

I have a Webform that contains a file element and am building a custom form to update the submission data.

I have found that when I submit my custom form I can load the Webform submission and set the file IDs and it will save the data fine with no issues.

However when it comes to removing a file after saving, the file I remove just remains attached.

I know that using the Webform interface the file upload / remove is working fine. However it seems to be a problem with removing files when updating the submission programmatically.

Is there any extra step I am missing to remove the files?

This is really simple version of the form I am building:

<?php

namespace Drupal\example\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;

/**
 * Provides an example form.
 */
class WebformFileUpdateForm extends FormBase {

  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'example_webform_file_update_form';
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $em = \Drupal::entityTypeManager();

    // Load all webform submissions for the node.
    $nid = 86552;
    $query = $em->getStorage('webform_submission')
      ->getQuery()
      ->condition('webform_id', 'tutorial', '=')
      ->condition('entity_id', $nid)
      ->pager(10);

    $submission_ids = $query->execute();
    $webform_submissions = $em->getStorage('webform_submission')
      ->loadMultiple($submission_ids);

    $form['#tree'] = TRUE;

    $form['files'] = [
      '#type' => 'fieldset',
      '#title' => $this->t('Files'),
    ];

    foreach ($webform_submissions as $submission) {
      $form['files'][$submission->id()]['file'] = [
        '#type' => 'managed_file',
        '#title' => $this->t('File'),
        '#default_value' => $submission->getElementData('attached_files'),
        '#upload_location' => 'private://tutorials/' . $submission->id() . '/',
        '#multiple' => TRUE,
      ];
    }

    $form['submit'] = [
      '#type' => 'submit',
      '#value' => $this->t('Update'),
    ];
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $em = \Drupal::entityTypeManager();
    $values = $form_state->getValues();
    foreach ($values['files'] as $sid => $data) {
      $em->getStorage('webform_submission')
        ->load($sid)
        ->setElementData('attached_files', $data['file'])
        ->save();
    }
  }

}

Answer 1

This issue replicable for anonymous users only, kind of caching issue so if you add following cache API function code in custom form , then latest submission data 'll be load that 'll be added/removed by user while interacting with custom form.

 $form['#cache'] = [
   'contexts' => ['session']
 ];