m16 R2, sleep, the primary display is doesn't turn on

This has happened a few times in the month or so that I've had my m16 R2. Occasionally when resuming from Sleep, the primary display is doesn't turn on, and is missing in Display Settings I'll Lock my device, come back a few hours later, and find that it doesn't resume from sleep correctly. The laptop's screen is black and never turns on again. 

This happened a couple of times when I had an external monitor plugged in. When that happened, the external monitor would work. If I then opened Display Settings, I would find that only the external monitor was appearing in the list of available displays. The laptop's built-in primary monitor wasn't even listed among the display devices.

Is this a known issue? Are there any steps to resolving this? This doesn't happen every time I let the laptop sleep. But when it does occur, I'm forced to hard shut down the laptop if I don't have an external monitor handy.