BuddyPress.org

I have a registration form on my frontpage where I want users to register at.
I assigned my official buddypress registration page to /register, so naturally I have my frontpage signup form directed to that page.
Next I’ve put in every single input element that the original form has, but everytime I sign up it gets redirected to the frontpage.

I looked at the form over and over, but it’s an exact copy of the original form (including the hidden input). Is there some other check build in? How can I easily avoid that?