Contoso uses Microsoft Entra Connect with Pass-through Authentication (PTA) enabled. The organization has deployed a single PTA authentication agent on the Entra Connect server. During a recent unplanned reboot of that server, users were unable to sign in to cloud applications until the server came back online. The identity team must ensure user sign-ins continue to succeed even if one server hosting an agent becomes unavailable, while keeping password validation on-premises. What should the team do?