Style issue on single question

You need to add content wrapper that provide your theme. please see the code here
https://pickplugins.com/docs/documentation/question-answer/faq/single-question-page-full-width-issue/

after checking your link here is code should work.

    add_action('qa_action_before_single_question', 'qa_action_before_single_question', 10);
    add_action('qa_action_after_single_question', 'qa_action_after_single_question', 10);
    function qa_action_before_single_question() {
      echo '<p class="site-description" itemprop="description"><?php bloginfo( 'name' ); ?></p>
<div class="content-sidebar-wrap">
  <main class="content">';
    }
    function qa_action_after_single_question() {
      echo '</main>
</div>';
    }

Also i noticed, sidebar isn’t showing. have you removed it?
Regards