Before explaining why some devices appear on the ThinMan console with the status Unmanaged, it is necessary to explain the information shown on the ThinMan License Manager.
Open the ThinMan License Manager (menu Tools -> ThinMan License).
On this window you will find the following information:
When the number of licenses that ThinMan can manage is lower than the number of devices detected by ThinMan on the network. See image below.
You will observe on the ThinMan local console, the devices status as Unmanaged.
To solve this problem, you need to extend your ThinMan license in order to include more devices (contact your sales reference). Then, upgrade your ThinMan License through the License Management.
On the above example, after upgrading the ThinMan license, no device will appear with status Unmanaged.