Client was running a couple of different php-fpm versions and after a system update, php7.3-fpm and php7.4-fpm exhibited failed systemd units interchangeably. Upon tackling the project and after much digging, I found that,
Failed systemd units
their "/etc/php/7.3/fpm/pool.d/www.conf" and 7.4 configurations were listening to the wrong php versions respectively.
Line 5: php 7.4 listening to php 7.3 socket, causing the disruption.
Fix:
After making the correct changes, restarting both services resulted in the desired output.