My brand new s7 edge restarts at random intervals

[AC Question]

Whenever I'm using my phone the screen goes black then shows the image of a lock and a circle around it turning in different colors, then the screen turns back on in the lock screen and asks for my password instead of the fingerprint, as if it was restarted. I don't know if this is a security feature of the phone, also this only happens whenever I turn on my phone and get through the lock screen after some seconds it does this. It happens at random intervals one happened to me at 3 am when I checked something on my phone, and in the morning, it seems to happen once a day.
Thanks in advance