Question nginx proxy in front of apache - nginx became disabled

[TomBoB]

Server operating system version

AlmaLinux 8.7

Plesk version and microupdate number

Plesk 18.0.51 #1

One of our servers was shut down briefly and then fired up again for maintenance of the underlying infrastructure. Everything worked perfectly except Nginx. We use it as a proxy in front of apache.
Problem was found and resolved quickly, no issue.

My question is, under what circumstances would Plesk change - apparently all by itself - the config to
NGINX_ENABLED=no

To be clear, it was not NGINX_ENABLED without any value, as mentioned in some support articles, it had the value "no".

[Cross post from the Plesk facebook group]

 

[Peter Debik]

Is or was Litespeed installed on the server?

 

[TomBoB]

no litespeed, no. All our servers use nginx in front of apache.