Mir Ali,
So two things pop into my head based on the above screenshot. First, do you have any NAC Appliances added to the system? I don't see any in your screenshot to the left of the picture.
Second, Lost-Carrier generally means that RADIUS accounted reported that the end system was disconnected. Lost-Carrier I think is generally for wired switches when the end system disconnects.
Can you provide more info about your environment and how it's configured?
Thanks,
Tyler