Enrollment starts only after reboot

Hi

When I enroll a computer with DEP I need to go trough this steps:

1. Run setup assistant (accept configuration, create account etc.)
2. Reboot
3. Wait until enrollment starts

Why do I have to restart the computer?

PreStage Enrollment looks like this:

Use existing location information, if applicable --> checked
Require Authentication --> unchecked
Make MDM Profile Mandatory --> checked
Allow MDM Profile Removal --> checked
Allow the user to remove the MDM profile --> checked
Restore --> checked
Apple ID --> checked
Terms of Service --> checked
Diagnostics --> checked
Registration --> checked
Filevault --> checked

Anybody knows how to prevent this behaviour? Would like to have a workflow like this:

1. Run setup assistant (accept configuration, create account etc.)
2. Wait until enrollment starts
3. Run all policies triggered with "Enrollment Complete"

Best
Anver