A form like the following is expected to show additional fields when user selected "Yes" in the "Show more" radio button. When shown, the more section has a "Name" text field, and a "Gender" radios set.

But it never works as expected. The "Gender" label will be there, but the radio buttons are never rendered. I know changing "Gender" into radios would work, but for some reason, I need to use multiple radio buttons. Is there any way I can make this work?

<?php  namespace DrupalmymoduleForm;  use DrupalCoreFormFormBase;  class DonationPrepareForm extends FormBase {    /**    * {@inheritdoc}    */   public function getFormId() {     return 'my_form';   }    /**    * {@inheritdoc}    */   public function buildForm(     array $form,     FormStateInterface $form_state   ) {     $form['show_more'] = [       '#type' => 'radios',       '#title' => 'Show more',       '#options' => [         'Y' => 'Yes',         'N' => 'No',       ],       '#ajax' => [         'callback' => '::ajaxBuildForm',         'wrapper' => 'edit-more-wrapper',         'progress' => [           'type' => 'throbber',           'message' => $this->t('Loading...'),         ],       ],     ];     $form['more'] = [       '#type' => 'container',       '#prefix' => '<div id="edit-more-wrapper">',       '#suffix' => '</div>',     ];      return $form;   }    public function ajaxBuildForm(array &$form, FormStateInterface $form_state)   {     if ($form_state->getValue('show_more') === 'Y') {       $form['more']['name'] = [         '#type' => 'textfield',         '#title' => 'Name',         '#required' => TRUE,       ];       $form['more']['gender'] = [         '#type' => 'radios',         '#title' => 'Gender',         '#options' => [           'M' => 'Male',           'F' => 'Female',         ],         '#required' => TRUE,       ];     }     return $form['more'];   } } 

Same question extends to other composite form elements (e.g. Checkboxes). Is there any way to make AJAX work for them?