Rivian alerted me that there was a service action related to the hub, and while waiting for that appointment, the hub came loose while driving and began grinding against the brakes and went into full system shutdown. The truck needed to be towed and the hub and brakes needed to be replaced. The truck was undrivae while driving at highway speeds and could have crashed. When questioned, the service center reiterated that this was not a recall but simply a head up. The repairs were covered under warranty.