Hi donnaa5dcp, I'm Sergio, it's a pleasure to help you.
First, you should change your account display name.
1. Sign in to the Your info page on the Microsoft account website.
2. Under your name, select Edit name. If there’s no name listed yet, select Add name.
3. Enter the name you want, then type the CAPTCHA and select Save. Some names may not be allowed if they contain blocked words or phrases. If you get an error when you enter your name, try a nickname instead.
Source:
https://support.microsoft.com/en-us/account-bil...
If the display name doesn't change right away, or if the old name is still showing, your information may be cached. To get the name to update you will need to remove all cache files.
To delete all cache files, you follow these steps (in Windows):
a. Fully exit the Microsoft Teams desktop client.
b. Go to File Explorer, and (Windows 10) type in appdata\Microsoft\teams and remove all the content. In Windows 11 you type AppData\Local\Packages\MicrosoftTeams_8wekyb3d8bbwe\LocalCache and remove all the content.
c. You must restart the app and try again.
If the problem continue:
a. uninstall the Team desktop app.
b. Go to File Explorer, and (Windows 10) type in appdata\Microsoft\teams and remove all the content. In Windows 11 you type AppData\Local\Packages\MicrosoftTeams_8wekyb3d8bbwe\LocalCache and remove all the content.
c. Reboot the computer and install the Team desktop app again.
If you are using the Teams web app, then you need to remove the browser cache and cookies.
Greetings.
