We are an Adobe partner supporting a client who is migrating from ProofHQ to Workfront platform/Workfront Proof. When attempting to provision new users in Workfront Proof, login defaults to the wrong account (a partner account tied to the login email), and is unable to navigate to the client's instance of Workfront Proof. How can the user get access to the new Workfront Proof instance, without jeopardizing the existing login credentials to their partner instance?