Model: R8000P|Nighthawk X6S AC4000 Tri Band WiFi Router

Currently using R8000P router nighthawk ,v1.4.1.50_1.3.10 , and my problem existed also with the previous firmware version  . Whenever I reboot the router it sends me back to the original settings and then I have to set up the router again changing back to my network name and password . Not sure why this is . Frustrating as it is stable otherwise . Any ideas ? 

ThanksTim