issue with search in the second language

Hi,
I have a search feature in my website that works well both in default (french) and second (english) languages when I am logged in to my admin panel. but when I log out or use another browser, all searches redirected to the default page.
I really appreciate it if you can help me how to fix this issue.

* when I search /?s=query is called but if I am not logged in always redirected to /fr/search/query instead of /en/search/query (when in english side)

The page I need help with: [log in to see the link]