E-mail authentication: Email already exists. Please use another email address

Hello,

We have implemented https://github.com/PeterGFernandez/auth0-verified-email-address-change. However login fails when a user logs in using the email provider with a previously used, but now deleted, email user with the following error message:

Email already exists. Please use another email address.

The corresponding e-mail address cannot be found in either user management or the user export.

This looks and feels like a bug.