Rhino devices are configured from factory to automatically power down should the device remain on the Welcome screen of the setup Wizard for more than 20 minutes.
The typical scenario this addresses is inadvertent powering on during transit, wherein a device may otherwise arrive at a customer location with no remaining battery life. This can cause delays for staging, setup, and other time-critical tasks.
Equally though, this means devices which are switched on and left in a staging environment may automatically power down if not interacted with often enough. In future this may be configurable. For now, please either interact with the device every 20 minutes, begin moving through the Setup Wizard, or undertake managed provisioning within 20 minutes of powering on.