If you look at the inventory record for that machine at the time that it is trying to resolve that value, is the value blank? If it is right after provisioning, there may not be a full Inventory record yet, and that info may not be present.
This was so far back I cannot say for certain. I will mark this as answered.
I guess provisioning will be a thing of the past anyway
OSD Scripts are what is getting deprecated, Provisioning is getting huge focus right now and is the preferred method for imaging and migration tasks now and moving forward. So if there is a problem with the variables resolving we want to get it sorted out. Let me know if there is anything else we can help with on this.
Thank you for the correction