Why removes all html code of the component?

Question

AJAX

I use the standard feedback form component:

<?$APPLICATION->IncludeComponent("bitrix:main.feedback","",Array(
                      "AJAX_MODE" => "Y",
                      "AJAX_OPTION_SHADOW" => "N",
                      "AJAX_OPTION_JUMP" => "N",
                      "AJAX_OPTION_STYLE" => "Y",
                      "AJAX_OPTION_HISTORY" => "N",
                      "USE_CAPTCHA" => "N",
                      "OK_TEXT" => "Спасибо, ваше вопрос принят.",
                      "EMAIL_TO" => "[email protected]",
                      "REQUIRED_FIELDS" => Array("NAME","EMAIL","MESSAGE"),
                      "EVENT_MESSAGE_ID" => Array("7")                      
                  )
              );?>

After submitting the form, the content of the frame tag is empty: the form code before submission also disappears. The letter from the form safely at the same time comes.
<div id="comp_2345234523452345"></div>