I have a WLC and having some SSIDs for Flex-connect mode (Mobility-group). Users trying to connect the wireless network using BYOD device but while they are trying to connect , it spins and spins . I checked controller , client is connected and got IP address and some users not but client says it spins and spins .No authentication prompt or no IP address

Can anyone help me how to proceed to fix this issue .

WLC : 2500