After the Nougat update my power button intermittently stopped working, i.e. unable to turn screen on or if it is on, turn it off. Holding it down does nothing. After charging it for a bit, the problem seemed to go away. It was over 60% charged when I noticed the problem. Similarly, the home button either did nothing or opened Google assistant (did not hold the button, simply tapped it). I powered off and on. I cleared the cache. Yet the problem still persisted. For NOW, it seems to have returned to working normally. Only thing I did was let it charge for about 30 minutes during a car ride. There is something unstable in the code.