Signals Notebook: Locked out of one tenant after changing the e-mail in another tenant

Details: After changing the e-mail in the TEST tenant the user sees the following error message when trying to access the PRODUCTION tenant: "You need a license to access this application"
This happens because changing the e-mail in one tenant changes the data in the Signals Notebook authentication system, the user will not be able to log into any tenants with the old e-mail.

Solution: The Administrator of the other tenant (PRODUCTION) needs to update the user's e-mail to the new address.