You didn’t mention your process, but if you are using sysprep and have your reference unattend.xml file in the right locaiton it should work.
Look over this thread, it give you a sanitized unattend.xml file as well as the sysprep switches.
FWIW I use the unattend.xml file to name the PC and connect it to the domain and not the fog client, so I know this route works.