Windows 10 Upgrade Fails at Various Percentages.

Hello,
I am trying to upgrade Windows 10 Enterprise from 1703 to 1809 using SCCM Current branch on Surface Pro 4 and Surface Pro 5.
I have just published the upgrade to a collection which will then appear in Software Center "Updates".
The update is received and installed and you then get prompted to reboot.
Once rebooted the upgrade hangs on around 75% or 79%. The upgrade never completes and you have to power off\on and Windows remains on 1703.
Some upgrades have worked and have successfully completed, but it seems I have a batch that has issues.

I have tried the following:
1. Increased the maximum runtime to 240min (Made no difference)
2. Installed the latest Surface Pro driver and firmware pack (Made no difference)
3. Ran Microsoft Fix it tool which did delete the MS update datastore and created a new one (Resolved the issue on a few but not all – Not a solution)
4. Ran Setup.exe from the VLSC Windows 10 Enterprise iso. Same issue gets stuck around 75% or 78%.


I have attached the setuperr.log and a screenshot of the error which presented with running setup.exe from the iso.

Be grateful for any help.

Thanks
Matt
setuperr.log