Etm571
I do have auto-reboot enabled, but it has been enabled for a long time, and I've never really noticed it. Only in the past few weeks, with no changes in Android Settings, has this behavior began.
doublefree
It's happened most often that I've been on my device, I set it down, then notice the screen change in my peripheral vision and look down to see either the Google or GOS logo, and the boot process. Or, I'll put my phone in my pocket, pull it out again within minutes, and be required to enter my PIN because of a reboot, with my launcher process starting as the phone unlocks. I think it has rebooted a few times while I've been using it, but it's mostly just around activity.