Nexus 6p screen blinks off and comes back on every 5-6 seconds

My Nexus 6p started doing something strange. whenever I am using it, for reading, playing games, etc, the screen will shut off by itself and come back on. it does this every 6 seconds, and it's very annoying. I have hard reset to no avail. I searched the forums and all I see is "flickering" or where the phone screen is OFF, and it randomly comes back on. My problem is the opposite. When the screen in ON, it blinks off for a second or two and comes back on. Can anyone offer any suggestions?