Bitrix disables facet index for products?

Question

1C-Bitrix

Can you tell me why the facet index is reset for products? I create it, after a while it is in the DISABLED status. and so constantly.

I suppose that because of the non-standard exchange between 1C, but this appeared recently, and we have not touched the exchange module for more than six months and everything was fine.

Prices, balance, VAT, multiplicity and part of the element properties are updated in the exchange module,
here is the part from the exchange module where the element is affected:

...
\Bitrix\Catalog\PriceTable::add(Array('PRODUCT_ID'=>intval($arFields["ID"]),'PRICE' => $arData["PRODUCT_PRICE"],'PRICE_SCALE' => $arData["PRODUCT_PRICE"],'CURRENCY'=>'RUB','CATALOG_GROUP_ID'=>1));
...
CIBlockElement::SetPropertyValuesEx($arData['PRODUCT_ID'], $arData['IBLOCK_ID'], array('MINIMUM_PRICE' => floatval($arData["PRODUCT_PRICE"])));
CIBlockElement::SetPropertyValuesEx($arData['PRODUCT_ID'], $arData['IBLOCK_ID'], array('MAXIMUM_PRICE' => floatval($arData["PRODUCT_PRICE"])));
...

\Bitrix\Catalog\StoreProductTable::update($arStoreProduct['ID'], Array('PRODUCT_ID'=>intval($arFields["ID"]),'STORE_ID'=>1,'AMOUNT' => $arData["PRODUCT_QUANTITY"]));

...

$catalogUpdateFields = ['QUANTITY' => $arData["PRODUCT_QUANTITY"]];

if(COption::GetOptionString(self::MODULE_ID, 'AGENT_EXCHANGE1C_VAT')=='Y'&&$arData['VAT']!=''){
$catalogUpdateFields['VAT_ID'] = self::$arVat[$arData['VAT']];
$catalogUpdateFields['VAT_INCLUDED'] = 'Y';
}

CCatalogProduct::update($arData['PRODUCT_ID'], $catalogUpdateFields);

$iblockUpdate = \Bitrix\Iblock\ElementTable::update($arData['PRODUCT_ID'],['TIMESTAMP_X'=>date('d.m.Y H:i:s')]);
...