PHP stops working unexplained on IIS with Fastcgi

Question

I recently updated a site that was written in classic ASP on the IIS of Windows 2008 Server, I changed the programming of the site to PHP and kept running on IIS via Fastcgi, while the site was in homologation I had no problem, but when putting into production, at least two or three times a day PHP stops working (The areas of the site that are still in ASP continue working, only the pages made in PHP param), no error appears in the browser (only gives timeout) or PHP LOG. The only way to get back on the air is to restart the OSI. I have already upgraded from PHP 5.4 to 5.6 and the problem persists. As the problem only started to happen after the site has already entered into production, I thought it could be some hardware bottleneck, however, when it happens the server is always with only 5 to 10% of processing use and the memory never reaches 50%. Out that already happened at 2:30 am, when the site has almost no access.

Here are some images with basic PHP settings in IIS and also the php.ini file.:

And here is a link to see the complete "PHP.ini" file: php.ini

Has anyone ever been through the same problem or has any idea what it’s about?

Thank you!