How to get section ID in Bitrix directory with Ajax enabled?

Question

AJAX

Hello colleagues. I can not overcome one problem in any way.
Site on Bitrix. There is a section, in the index file I prescribe the output of the catalog and the news in detail. I need the news to be displayed ONLY in the root page. It is displayed both in sections and in elements in detail.

<?if($APPLICATION->GetCurDir() == '/bla-bla-bla/'){?>
    );?>

Works every other time, because ajax is enabled in the directory.
As when trying to display $APPLICATION->GetCurDir() and see how the code works, it shows the section correctly only once, on the first visit. All this is clearly related to ajax.
Can anyone tell me how to get the current section in this version?