🇵🇱Poland @ufol666

I also have this problem, I could not find anything in the options.
preporcess solved the problem:

function YOURTHEMENAME_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
  if ($form_id == 'YOURSIMPLENEWSFORMID') {
     $form['langcode']['#access'] = FALSE;;
  }
}