In order to improve headers sent to php-fpm, is necessary to add manually an extra directive to php-fpm The original template vhost.conf.master an extra parameter can be added in order if you make reconfigurations from panel, this extra parameter is deleted.

ispconfig/server/conf/vhost.conf.master

lines 353,356,407

we found something like this: FastCgiExternalServer /usr/lib/cgi-bin/php5-fcgi -socket /var/run/php5-fpm.sock -idle-timeout 3000 -pass-header Authorization

New feature will be like this FastCgiExternalServer /usr/lib/cgi-bin/php5-fcgi -socket /var/run/php5-fpm.sock -idle-timeout 3000 -pass-header Authorization -pass-header Content-Type

add -pass-header Content-Type at the end

thank you