Internalization in Django works locally, but not on server (AWS EB)

As the title says, Django's internalization works locally (with python manage.py runserver), but not on Amazon's Elastic Beanstalk.

How can I fix it?

p.s. Besides, something strange is happening: in one template among other things I translate "Save" into German as "Speichern", on the server I see only "Save" was translated, but into ... "Sichern" (it's synonymous), however, I din't use the word "Sichern" anywhere in my project (I ran grep -rnw . -e "Sichern" to be sure).

It means that Django picks it up from somewhere, right? It also means that the server recognizes that the request is in German.