When you schedule a job in the GSS Console and WOL for inactive computers is not selected. The AXengine it will not update PXE to allow automatic boot into the correct automation environment. .
If the engine does not send out WOL packets for inactive computers, it also doesn't update the PXE tables. If the option is set too low, under 3 minutes, this issue can occur as well.
If there is a working production os the system should power on and then boot to production. Once booted to production the client should reboot and then be booted back to PXE as long as boot from network is the first boot option.