Netgear Nighawk model ex 8000

[KaiFxD6]

I need help, my Nighthawk used to work but one day I was having bad internet so I unplugged it, it logged me out and when I plugged back in It says it could not connect to my mobile device when I pressed New device setup and I also pressed the reset button and held it

[plemans]

what firmware is on the extender? 

What router are you connecting it to? 

Are you setting it up using wps or the installation assistant?