Hi @Thomas Schmidt ,
To narrow down the problem, we need more information.
1, What version of the ADK and Windows PE are you using? What version of the OS image are you deploying? We can try to install another version of the OS image on a test computer.
2, Please check SMSTS.log and relevant logs, if there are any errors. Besides, don’t forget to map it out before the client restarts.
Depending on the deployment scenario, SMSTS.log may reside in %TEMP%, %WINDIR%\System32\ccm\logs, or C:_SMSTaskSequence, or C:\SMSTSLog.
For more details about logs, please refer to this link:
Troubleshoot MDT - Configuration Manager | Microsoft Learn
Looking forward to your reply.