This was happening to me. For some reason mine would wake up and the camera would be turned on. I turned off the ability to swipe down on the lock screen and the problem stopped. Something was triggering a "swipe down" and waking it up to the camera.
Not sure if that will help you but I thought I'd throw it out there.
I looked to see where you could control swipe down on lock screen and didn't see any. I come out of sleep by just pressing the Enter button. If I swipe down, it turns the camera on and displays what the camera sees and shows a button to press to unlock.