Galaxy J7....Is Timing Out After Just A Couple Seconds

[yamaha15074]

Merry Christmas Everyone......Well I Got A J7 For Christmas, And It's Driving Me Crazy.....I can't Figure Out Why This Phone Is Timing Out...Going To Sleep...Whatever After About 8 Seconds..?
I've Googled It....Most Responses Say Do A System Reboot....
I Have The Timeout Set For 5 Minutes, I've Taken The Security Lock Off...
Any Help Would Be Appreciated

Thanks