[MM3-users] user self registration

Spammers have been registering and not subscribing. I want to turn off the user self registration at https://lists.ccalternatives.org/mailman3/ .

I edited /etc/mailman3/settings.py adding ACCOUNT_ALLOW_REGISTRATION = False and restarted the services, but the ' Sign Up' option remains. I assume /etc/mailman3/settings.py is my active settings file.

What am I doing wrong?