BIOS time randomly changing when trying to build devices

[Gibbop1]

On receipt of a device a build engineer starts the device in BIOS and sets the local time and settings. We then use SCCM to wipe and load Window 10 x64 to the HP device. The process first formats the disk to UEFI then lays down the vanilla Windows WIM & device drivers. Once this is done Windows is automatically booted (with an unattend file) into Audit mode and syspreped to OOBE. When it boots back to OOBE a provisioning pack is used to finish the config e.g. joining to the domain and installing SCCM client etc. This works fine around 90% of the time but 10% of the devices fail at the provisioning stage because the BIOS date and Time has changed to US standard time.

Any ideas why this would be the case?

Many thanks,

Gibbo