Laravel blank white screen - Centos 7, NGINX and PHP7.1

I have developed a Laravel app using PDT in Eclipse. Everything runs perfectly on my development machine. I have deployed to a Centos 7 server running PHP 7.1, PHP-FPM in socket mode and NGINX and all I get is a blank white screen. If I set up another virtual NGINX site with just a phpinfo() script then it works so I know that PHP is working fine.

I have researched all the answers I can find and have tried all the usual things relating to permissions on the storage directories and bootstrap/cache directory etc.

Nothing is written to the storage/logs directory and there are no errors in the NGINX logs or the PHP-FPM logs. Without any indication of what is happening, I am now lost as to how to proceed to find the source of the error

If I start a server using:

php artisan serve 

then the application runs without any issues!

What other debug/trace methods can I use to find the source of the problem?

Thanks

via Chebli Mohamed