Hello TomScheike,
Thank you for reaching out to Microsoft customer support. I understand that you are experiencing an issue with deploying group policy objects in Windows Server 2019, specifically with creating a scheduled task that runs under the System account.
Based on the error message you provided, it appears that there is a problem with mapping account names and security IDs between the German and English versions of Windows. This is a known issue and our development team is working on a fix for it.
In the meantime, as a workaround, you can try using the English version of the account name "NT-Authority\System" in your GPO instead of the German version "NT-Autorität\System". This should allow the GPO to apply successfully on both German and English systems.
I hope this information helps. If you have any further questions or concerns, please don't hesitate to let me know.
Best regards,
Qiuyang