Deployment very slow after first reboot

Question

Hi everyone,

Over the past 12 months or so, I have noticed that after the first reboot in an MDT Windows 10 offline deployment (1909, then 2004 now 20H2), the machines all sit at "getting ready" for up to 40 minutes. This is on multiple models from multiple manufacturers.

I've looked in the MDT logs, and all I can see is something like the following each time:

LTI initiating task sequence-requested reboot. LiteTouch 22/12/2020 11:18:35 0 (0x0000)
Property LogPath is now = C:\MININT\SMSOSD\OSDLOGS LiteTouch 22/12/2020 11:52:06 0 (0x0000)

So it looks like it is Windows itself causing the slowdown.

In event viewer, once the deployment completes, all I have found so far is lots of

"The Network List Service service terminated with the following error:"
"The Device is not ready"

Could this be some sort of driver issue? Once I get into Windows, the network drivers are there and the behaviour is the same on desktops with no active network connection and on laptops with a wireless card.

Any pointers would be wonderful,

Thanks!