Admin language auto-detection problem

I found something odd. I am working on a site that is purely english, no admin translation required. therefore I used settings.adminLanguages = [ "en" ]; in my config.cfc. This works nice as it should only display the admin in english and no dropdown for languages in the menu. however the system seemed to determine, either based on a cookie or on something else that i need german and switched to german. I can no longer switch back to english. I think while checking and applying the user language, the config setting is not evaluated.