Hosting, cPanel all settings will be the same for all sites by default.
Two identical sites are located in adjacent folders. Both have version 4.16.2. One site was installed immediately as 4.16.2, the other was updated from 4.14. Two identical pages.
The server response, one is about 50 ms, the other is about 500 ms.
Where is the server response speed configured?
I think the only option in CS-Cart that may directly affect page loading speed is “Rebuild cache automatically” in theme settings. So if you’re getting inconsistent loading times, check if this option is not enabled.
server settings are the same
Then I think you should contact server provider. If both sites are indeed the same, I think it’s not CS-Cart that is causing one to work slower than other.
This is shared hosting, cPanel, server settings cannot be changed. The provider claims that the settings are the same for both sites.
The provider demonstrated that setting up X-Nginx-Upstream-Cache-Status can be done using a script on the website.
The “fast” site turned out only on version 4.16.2
On all others (several sites installed) the usual 400-500 ms and X-Nginx-Upstream-Cache-Status: MISS
Structurally, the sites are the same, but they use different versions of cs-cart.
The “fast” site has version 4.16.2 installed.
Other sites have older versions or have been updated from an older version.