{browser_lang} problem detecting some language settings

[HarmO]

Hi,

i 'm creating a multi-lingual website (again) and i noticed some weird behavior of the {browser_lang}-tag.

i want to do a browser lang detection to redirect visitors to the right homepage and if my language is dutch ('nl') or french ('fr') it works fine.

BUT since it is a website for belgium it is possible that the language is dutch/belgium ('nl-be') and this is where the problem is: 'nl-be' is not detected, instead English ('en') is detected.

Is this a bug?