In a possibly related issue, I've got two Lenovo laptops that will boot in their respective docking stations, but after a few seconds, goes to sleep after logging on.
You need to hit the docking station power button to wake them up. This may be related to:
Any thoughts on this?
I tried installing dconf-editor, and changing the behavior so nothing happens when the laptop is closed and on AC power, but the behavior didn't change.