Hi,
I've migrated a clean WHMCS 7.4 to a new server running plesk onyx 17.5.3 centos7.
This server is clean as well and planned to be dedicated for WHMCS. The whmcs got only 2 clients (tests) and a brand new design we created.
Server is 16GB Ram, 4 cores, 160SSD, Reversed NGINX + Apache.
I can't understand the problem, the loading time is huge, takes 30 seconds to load login. Confirmed it in pingdom pagespeed test.
I tried to disable modules (got only 2), theme... didn't help
Please help me, how can I determine the problem?