Overview
When sending an invitation to use the google-oauth2 connection method and using the + method (username+google-auth-test@tenant.com), the below message is received:
The specified account is not allowed to accept the current invitation
There are no issues if just the base email is used or username@tenant.com.
This article clarified whether there is a way to use the + in emails, considering the need of some customers to always create different emails for testing.
Solution
At the moment, there is no available workaround for this situation. Only the use of the actual email account to invite users will work.