Galaxy S6 - Interesting problem?

[EricandSuebee]

So the past couple days can't figure out why its happening but every so often I'll be using my phone and go to close out of a app and nothing happens, then boom the screen goes black for a sec then i'm looking at my lock screen, it's as if the phone just restarted. What could be causing this? Never did this at all before, would love to track down the issue so I can put a stop to it.

 

[EricandSuebee]

Anyone at all have any suggestions?