Nighthawk router changed network name and password back to default

[sgnoco]

Suddenly my router changed both the network name and password back to the default.  I've been able to go back in and change the network names but it won't let me change the password.  When I use the Nighthawk app it gives me an error on the original password saying it is in the wrong format even though it is the password that is on the router and is the password that is working.  I feel like I'm in some weird catch-22.  And of course Netgear has no support for out of warranty products.

Help!

[FURRYe38]

Confirming you have the C7000 modem? 

Has a factory reset and setup from scratch been performed then save off a backup configuration to file for safe keeping? 

https://kb.netgear.com/24231/How-do-I-back-up-the-router-configuration-settings-on-my-Nighthawk-rout...