I have a number of Pogoplugs v4 and mobiles, and I have noticed that whenever a mechanical HDD is used as the boot drive (USB 2.0) it fails to boot when issuing the reboot command. The light will sit there flashing. If you unplug the device and plug it back in, it boots fine.
My suspicion is that the Pogoplug is trying to access and boot from the mechanical drive more quickly than it is ready when rebooting. Is there a way to make it wait longer before trying to boot to see if that helps?
Thank you in advance.