all devices in LMS are in the UDM ("Unified Device Manager") - no matter how they got there (by discovery, manual add, db restore, etc.)
how the application treats the devices depends on their state. Here is a list of the different states a device can have in LMS:
Understanding Device States
the "Device Management Policy" can be setup in Inventory > Device Administration > Device Allocation Policy
and see if you have enabled "Manage By Groups"
for details have a look at Configuring Device Management Policy
