CS-Cart Varnish Add-on – ESI Login/Logout Issue on CloudPanel

[Nemesis]

I'm using CS-Cart 4.17.1 with the built-in Varnish cache add-on on a CloudPanel server (Ubuntu 22.04).
Varnish is installed and running correctly on port 6081, and everything seems to be configured as expected in Nginx and VCL.

However, ESI (Edge Side Includes) like login and logout don't work — for example, I can't log out after logging in.

This setup worked fine on version 4.16.1, but stopped after updating to 4.17.1.
Has anyone run into the same issue?

 

[Rootali]

Yes — this is a known behavior with the CS-Cart Varnish add-on after 4.17.1.

Solution:
Add the following header to your Nginx config under the location / block:

add_header Cache-Control "no-store, no-cache, must-revalidate";

This prevents Varnish from caching login-related responses and allows ESI to function properly.
Let me know if it works for you too.