Symptoms

PHP files are getting downloaded when selecting 'FPM application served by Apache' in domain PHP configuration.

Apache modules is not listed as loaded, the following command does not provide an output:

~# apachectl -M  | grep -E 'proxy_module|proxy_fcgi'

Cause

Necessary apache modules required for php-fpm support were not loaded.

Resolution

Make sure that proxy_fcgi_module and proxy_module are enabled and loading by apache.