It seems you have my same problem and I have solved just unplugging the adapter from the power, waiting for some time (1/5 minutes) and then replug the adapter to the power. Hope can bne helpful for...

Model : Hardware Version : Firmware Version : ISP : Hi there, I have bought time ago two kind of adapters (AV600 nano Powerline andAV500 Nano Powerline). They work, but I have noticed that...