Wifi extenders N300 no longer recognizes password

Hello,

I have 3 N300 Wifi extenders, and after an electrical outage due to a snow storm, none will connect with the router. I see the various extenders on my Mac, but when I try to connect to any of them, all 3 ask for my password. When I type in it in, it doesn't connect and sends me a message that the password is invalid, which it isn't. I have reset all the extenders to the factory settings, but the same thing happens. The lights turn green as normal and both my computer and iPad recognise the devices, the extenders search for a signal but never connect.  I have repeated these actions a number of times and always within 3 feet of the router. I have also tried using the NETGEAR Genie - nothing seems to work. Please help.

Thank you.