Quoting Romain:
> As you can see at https://lab.nexedi.com/nexedi/erp5/blob/master/bt5/erp5_web/ToolTemplateItem/caching_policy_manager.xml
> , caching policy manager often set Cookie in the Vary  header.
> For the CDN, it means that each query on the same URL but with a
> different cookie will never be a HIT, and so, query will always access
> ERP5 backend.