Issue #3486132: Fix call to a member function getSection() on null

src/EventSubscriber/LayoutBuilderIdsConfigureBlock.php

@@ -57,7 +57,8 @@ class LayoutBuilderIdsConfigureBlock implements EventSubscriberInterface {
     ) {
 
       // Pull out the layout_builder_id from config.
-      $layout_builder_id = $event->getFormState()->getFormObject()->getCurrentComponent()->get('layout_builder_id');
+      $layout_builder_id = $form['#form_id'] === 'layout_builder_update_block'
+          ? $event->getFormState()->getFormObject()->getCurrentComponent()->get('layout_builder_id') : NULL;
 
       // Add the section id to the configure form.
       $form['settings']['layout_builder_id'] = [