The server uses a setup that separates request for the different sites into pools. To set up a pool for a new infosys instance you need to do the following:

• go to /etc/php/<version>/fpm/pool.d
• copy a .conf file from an older version
• update the copy with the new info
• reload the fpm service with sudo service php<version>-fpm reload

or to set up from scratch you can read https://gist.github.com/fyrebase/62262b1ff33a6aaf5a54