Client Link LED will not turn off

Ran fine for 6 months. Now I notice the client link led STAYS ON even after all wireless is shut down. First thing I suspected was an unknown wireless still connected. But if I power down the extender and reboot, The client link LED is now off. So I turned on a wireless device and the LED lit. When I turned the wireless device off, the Client LED remained on. I walked away for about 30 minutes and it was still on. I unplugged the extender again and rebooted it. Same thing. No client light until I connect a device. The Client link LED does not turn off unless I power down the extender. I have reset to factory several times, I checked to make sure I had the latest firmware. I recongifured the extender. I have been using Fast Lane Router-to-Extender in 5GHz only and Extender-to-Device in 2.4GHz only. Everything has worked and still does except the annoying Client LED use to turn off when all wireless was shut down. If I thought another unknown device was running  I would  see it again when I booted up the extender. Any ideas?  please contact me at rooster658@hotmail.com.......... Thanks in advance