Locale detection not working

[Oliver996]

I did activate the locale detection as it is described in the documentation docs/en/locale-detection.md, but it's not working. I also did try to add my own detector, but that also does not work for me. Furthermore, I did try different things with my own detector, even directly returning "en_US" and that also did not change anything. It still goes to the default "de_DE" locale. It is as if this configuration is ignored, but I did it as described in the documentation. Is there something missing in the documentation? I'm using SilverStripe V4.14 and the only other config change for fluent that I did is setting disable_default_prefix to true. I did remove my disable_default_prefix change, but it did not change the result. Thank you for the help.