This is wrapper class issue you might missed to add following code , you need to find the class for your theme and add following code to your theme funcitons.php file.

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 '<div  class="content-area">';
}

function qa_action_after_single_question() {
  echo '</div>';
}