It sounds like CTOS may not be the culprit. I suspect you have two different failures occurring at once - your NIC driver is not getting installed and also your unattend.xml script isn't being read by the OS.
Are you using an inject script action to copy in an unattend.xml to get you through mini-setup? If so it seems the script is not being read. I would put wait actions before and after the inject script action, then remote control the device being provisioned. During the wait periods, validate the unattend.xml is being copied into place correctly. Also ensure there are no other unattend.xml files already within the image somewhere. This document explains in more detail:
Regarding the NIC driver, do you have it assigned in HII? And HII is running in the Post-OS install section of your template? I'd suggest running HII in preview mode, and make sure the device ID you have it assigned to is actually being detected while in WinPE. Here is a doc on running HII in preview mode: