Welcome to the Microsoft Q&A Forum and thank you for reaching out to share your issue.
Regarding your question, I understand that you're looking to change display name without changing the email address. Based on my research and testing, here are the steps you can follow:
- For a business account: Log in to the Admin Center > Users > Active users → Select the user > Manage username and email.
- For a personal account: Go to account.microsoft.com > Your Info > Edit name
We hope this helps resolve your issue. Please let us know if you need further assistance.
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