I have an implementation of five nuts for handling touch screens and have scheduled a daily reboot using the command from the cmd [-r -t shutdonw 5]
On some occasions the NUC not start properly and displays the following error message.
intel (R) Boot Agent GE v1.5.43
Copyright (c) 1997-2013. Intel Corporate
Client MAC ADD : C0 3F D5 6B 88 CE GUID : 00193AD9 D434 E111 918E C03FD56B88CE
PXE-E51: No DHCP or proxyDHCP offers were received
PXE-M0F: Exiting Intel Boot Agent
Reboot and select proper boot device or inser Boot MEdia In Select Boot device and press a Key.
This message does not always appear, occasionally boot properly.
looks like the hard disk is not being found, so the NUC is trying other available boot methods, such as the network PXE boot you have shown above.
If the disk is mechanical, you may need to set a "spin-up delay" in the BIOS - though it's a little strange to need that on a restart, it's mainly for powering on.