No Radius Log-Off when Unit Powers-Off?

Hello:

The Peplink units do Radius authorization and accounting fine on logins.

However, given that the devices are mobile, and get turned off when a vehicle parks, it seems that Radius stops are not being sent. Obviously if someone does a logoff, the unit likely sends a Radius stop. However it seems all users stay logged in forever. Even rebooting the unit does not cause the disconnected users to be logged out. So, when looking at duration of connections and bytes transferred during a connection, Radius has no information.

This is peculiar, because if the unit knows when it went down last due to the internal logs, and if the users/mac addresses are no longer connected when the unit is powered back up, it could easily send backdated Stops to the Radius server.

Has anyone else encountered similar issue or a work around, or a config that I am missing on the Peplink side, perhaps?