Hello,
Thank you for posting in Microsoft Community forum.
Based on the description, I understand your question is related to downgrade.
You can change to certain other editions. You can change from Standard to Datacenter, or change from Datacenter to Datacenter.
But you can't change from Datacenter to Standard edition.
Here is the document for your reference:
Upgrade and conversion options for Windows Server | Microsoft Learn
Have a nice day.
Best Regards,
Molly