This module like other addons works in various PrestaShop environments. Whole workflow of the module depends on context (like prestashop version, hosting configuration, modules that you use). I can assure you that with clean and bug free environment every aspect of the plugin should work properly. Anyway, in some cases, some options of this module (and also other modules) may not work properly. Because of this - you can read here about most common problems and how to fix them.