I have many devices connected to my RE650. Originally the network created by the  RE650 was defined with the same password as my router. But now, when a device gets disconnected and I try to reconnect, a password is asked for and when I enter it I receive incorrect password as reply. I have now 2 PC's and 2 smartphones that I can not connect anymore to the range extender. Also, the Tether app does not find my RE650. Some devices that have not been disconnected lately still do use the range extender, probably because these devices have not been disconnected since a long time. I have already unplugged and plugged the RE650 in again but that has no effect.