I have an Indoor Camera Plus installed and accessible through primary account.  Wanting to share it with multiple users.  Have sent an invite to first shared user.  They received the invite, went through preliminary access process, downloaded app into Apple iPad Air running iPadOS 18.6.2 .  Successfully accessed the shared camera feed.  Logged out and attempted to log back in.  email, Password accepted, but verification code never received via email.  Get message that Device is not authorized and verification code can not be sent via email.  Suggesting authorization be done through 3rd party authorization service.  What is happening that they can not get back into their account?