SG-2100 must be manually power cycled after installation
The Reinstalling pfSense Plus Software document for the SG-2100 indicates that the unit will reboot automatically after installation in Step 9:
"The Netgate SG-2100 will automatically reboot to complete the installation. Remove the USB key when the console menu appears."
But, after installation, the user is prompted to Cycle the power to reboot. So, the instructions should read:
"Once the install has completed, remove the memstick, and cycle the power (unplug the SG-1100 and plug it back in) to reboot the SG-2100."