url when changing language

Hi,

I don't think that it's linked to HikaShop.

First, you say that you use Falang, but the language module switcher on your link looks like Joomla's module, not Falang's. So please check on that. If you use Falang, you want to use Falang's module.

Second, there are two ways to translate the menu items:
1. You have one menu item, and you use Falang's translation interface to change the text of the menu item for the different languages.
2. You have one menu item per language, and you link them together:
docs.joomla.org/J3.x:Setup_a_Multilingual_Site/Creating_menus

I don't know which method you used, nor do I know which method Falang recommends. You could try switching the method you use, but I would first recommend to check with Falang's support. They might be able to provide a better help than us on this as this issue looks like something Joomla menu items and Falang.