User migrated from LDAP, deleted from Auth0, can't re-migrate?

Does Auth0 keep some sort of hidden record of users that were migrated from an external DB into Auth0? I am seeing the following:

  1. User logs in, account is migrated to Auth0.
  2. For Reasons, I needed to delete the user from Auth0.
  3. Now they get an error “Wrong email or password.” when trying to log in again.

Have moved this conversation to a ticket to obtain further information. https://auth0.zendesk.com/agent/tickets/22797

Note: the root cause was found while reviewing the situation through another support channel so including it here for the benefit of others.

The issue was that an active blocked IP address was still in effect; removing it through the Management API resolved the situation.