New Venue does not wake up after going to Sleep

I am frustrated with my new Venue 11 Pro, because 9 times out of 10, whenever I set it to go to Sleep mode, or it falls asleep, it will not wake up again. It appears to go to sleep just fine, and I push the button once to wake it up, and it vibrates immediately for a half second. But then it never wakes up or goes on screen for many minutes. I try the power button again for longer, and eventually it boots up, and all my programs are closed and the computer has restarted unexpectedly. What could be causing the computer to not wake up again after sleeping? It happens whether my keyboard is attached or not, but if it plays nice, then pressing the Start button wakes it up.(It is rare that it will actually wake up from sleep.)