Teams User names are not displayed with desktop app teams and shown as Unknown user

Hi Jeyeline,

I recommend you to clear the cache in your desktop Microsoft Teams app and check if the issue still exists.

To clear the cache for the classic Microsoft Teams you can follow these steps:

1. If Teams is still running, right-click the Teams icon on the taskbar, and then select Quit.

2. Open the Run dialog box by pressing the Windows logo key + R

    

3. In the Run dialog box, enter the following path, and then select OK:

%appdata%\Microsoft\Teams

• Delete all files and folders in the directory.

• Restart Teams.
  
  

For the New Microsoft Teams you can follow these steps:

1. If Teams is still running, right-click the Teams icon on the taskbar, and then select Quit.

2. Open the Run dialog box by pressing the Windows logo key + R

    

3. In the Run dialog box, enter the following path, and then select OK.

%userprofile%\appdata\local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams

•  Delete all files and folders in the directory.

• Restart Teams.

Clear Teams cache - Microsoft Teams | Microsoft Learn