Check C:\Windows\Logs\CBS\CBS.log which version you have installed.
Search for Loaded Servicing Stack or look in the top of the file
Our machines with 1709 had 10.0.16299.843 when they crasched on the upgrade to 1803 and we could not enable VT-d. (KB4477136)
The 1709 with the newer 10.0.16299.961 upgraded to 1803 without turning of VT-d or Vt-x (KB4485448)
The machine on 1803 with Vt-d of worked after we got 10.0.17134.580 (KB4485449)
Are you on 1709 or 1803?