Former Devices
When a device moves from your account to another customer, you keep read-only access to its data for the time it belonged to you. The new owner sees the device's data only from the moment it was handed over.
The list
Open Former Devices in the menu. Each device shows the period(s) your account owned it, in UTC. start means from the device's first data.

The read-only view
Click a device number to open it. You see its alarm history, charts and historical data, and you can Download Data — all limited to your ownership period(s).

There is no live status, configuration, start / stop or alarm acknowledgement for a former device.