Once per day, users observe that Nginx caching is automatically disabled without anyone performing a change. After turning off Nginx caching, the log file will indicate such.
X-Ray log: /var/log/alt-php-xray/manager.log
11/12/2021 11:27:27 AM No nginx cache entry found for cpaneluser1
CloudLinux provides a feature called PHP X-Ray. This feature doesn't capture requests with caching enabled. Automatically once per day, X-Ray has a scheduled task to turn off Nginx caching.
Disable X-Ray for the affected user or set the option "allow_disable_nginx_cache" to False ( default is True, allowing X-Ray to change Nginx caching to Off ).
You can find more details about X-Ray tracing below for CloudLinux.