Language switch does not work on “first visit”

Hello again!

I found some strange behaviour, if you call the site for the really first time, the language switcher does not work. The links for both languages are the same (index without the “/en/”). After a reload it works as expected.

I tried to call the index pages second language with a clear link, but this link also works after the second try (first try still calls the index page in the default language).

I’m sorry i don’t know how to explain it better.