If a user attempts to register using the same email address (that they have already used to create an existing account), they are advised that a Self Account already exists with that email which cannot be used twice. This was part of a March 2021 product update to improve user’s profile security.
To solve this, Admins can prompt a password reset in Permissions Manager so that the user doesn’t need to create a new profile altogether, and any existing cases or previous requests will be kept with their original Self account.
https://support.granicus.com/customersupport/s/article/self-account-registration
