Why does my s7 turn itself off randomly when charging overnight?

[AC Question]

Hi

I have recently purchased the s7. The phone has been fine in general however occasionally when the phone is charging overnight it randomly turns itself completely off meaning alarms etc don't go off the following morning. It happens roughly once a week. Does anyone know why this is and how to fix the problem. The phone light flashes blue once unplugged?

 

[B. Diddy]

Welcome to Android Central! Is the phone completely powering off, or is it just going into some sort of deep sleep that is inappropriately also causing alarms not to go off?