PHP-FPM with mod_proxy_fcgi needs extra steps for streaming unlike using just APache’s mod_php.
Add the below code to your httpd.conf file using the Custom HTTPD Configuration section in Direct Admin UI:
<IfModule mod_proxy_fcgi.c>
SetEnv no-gzip 1
</IfModule>
<IfModule mod_fcgid.c>
FcgidOutputBufferSize 0
</IfModule>
