You may notice Apache logs with proxy_fcgi along with "The timeout specified has expired" and would like to get these resolved. It is best to determine those to prevent potential retries and load.
When seeing errors like the following in /var/log/apache2/error_log adjustments to Apache may be needed.
[Thu Nov 19 16:22:22.011567 2020] [proxy_fcgi:error] [pid 7442:tid 47611709007616] (70007)The timeout specified has expired: [client 126.96.36.199:11218] AH01075: Error dispatching request : (polling), referer: http://domain.tld/
In this situation, you may need to set ProxyTimeout to the same set for Apache under Timeout. The default setting on a cPanel server for Timeout is 300. You can add the ProxyTimeout setting to /etc/apache2/conf.d/includes/pre_main_global.conf and then restart Apache. The contents would be
and the following would be run to restart Apache:
Instead of modifying the file directly, this can also be inserted using WHM under "Apache Configuration »Include Editor". Under "Pre Main Include" select all versions then insert the change and click Update.