[Plugin: Secure Invites] Logged in users register new blog

I’m back to using the secure invites plugin but when a user is logged in they cannot access the register page to create a new blog. Can logged in users access the wp-signup.php page and not receive a “you must be invited to join this community” error message. Am I doing it wrong this time around or is this a potential bug? Thanks.

https://www.ads-software.com/extend/plugins/wordpress-mu-secure-invites/