Here is more information on what the different availability statuses mean:
In Use: indicates that a vehicle is actively charging.
Plugged In: indicates that a vehicle is plugged in, but its charge session may have stopped or waiting to start.
Available: indicates that the charger is not currently in use and is available to provide a charge.
Unknown: The status of this charger is unknown, it could mean that this type of charger does not report real-time availability data. You can still plug in to receive a charge.
Out of Service: indicates that the charger is not working and is awaiting service.
Note: if a station has been marked Out of Service, there have been reported issues using that charger and it is under active investigation or scheduled for repair.