I've used Cisco PI for confirmation on clients being on the wireless network and it has worked flawlessly until recently. I can just go see Clients and Users under monitoring and make a export report that goes i.e. 4 weeks back. But now I have an issue. Some Users who was associated with the network a week ago is no longer on the list of Users/Clients, despite searching for the exact same Username/ID no matter if it's in the Clients and Users filter or the Search bar up top. I have records going back half a year, so why are these few clients gone all of the sudden? It's like the history of the client/user is gone. How can this be, and can I prevent it from happening? Any suggestions will be appreciated. It is Cisco PI 3.6.0