Hi,
The System Management Container is not created automatically when you extend AD. Please check if the System Management Container is there or not. If it is not there, create it manually and delegate permissions as needed. Please refer to:
Installing Prerequisites for Configuration Manager
Note: The non-Microsoft link is just for your reference.
Thanks for your time. Have a nice day!
Best regards,
Simon
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.