Blank page when used with fibosearch

Hello,

I have the follow issue. When both plug-ins (fibosearch & squirrly) are active some product pages are totally blank. For sure if I deactivate one of them everything working fine again. Was already downgrade 6 version of fibosearch but the result is the same.

Can you take a look to this please!

Web console is empty no errors.
Server protocol (plesk) has the follow error:

AH01071: Got error 'PHP message: PHP Fatal error: ob_start(): Cannot
use output buffering in output buffering display handlers in
/var/www/vhosts/mydomaon.com/httpdocs/wp-content/plugins/ajax-search-for-woocommerce-premium/includes/Engines/TNTSearchMySQL/Indexer/Builder.php
on line 949', referer:
https://my domain.com/produkt-category/accessoires/

Best regards