You need to uninstall Teams and then process to clear the cache information. See below for details.
(Please conduct at your own risk.)

■ For Windows OS

Please sign out from the Microsoft Teams app before taking the following steps.

1. Uninstall Microsoft Teams
   ※ The procedure starting with uninstallation is guided as the Microsoft’s recommended method.
   1. Right-click the Windows icon at the bottom-left corner of the screen and open [Apps & Features].
   2. Uninstall the following two products from the Apps & Features list.
      ・ Microsoft Teams
      ・ Teams Machine Wide Installer
      ※ Click the product name and [Uninstall]. Try one at a time.
      ※ If you cannot find Teams Machine Wide Installer, follow the steps below after removing Microsoft Teams.
2. Clear the cache of Microsoft Teams
   1. Press and hold the Windows key, and then press the [R] key.
   2. When the [Run] dialog box appears, enter “%AppData%\Microsoft” in the [Open] field, and click [OK].
   3. Delete the [Teams] folder. ※ If you can’t, there may be some Office applications running such as Microsoft Teams, Outlook, Word, Excel, etc., which should all be quit.
   4. Similarly, press and hold the [R] key while holding down the Windows key, enter “%LocalAppData%\Microsoft” in the dialog box that appears, and click [OK].
   5. Delete the [Teams] folder.
   6. Reboot the PC.
3. Reinstall Microsoft Teams
   Access the following URL and install the latest version of Microsoft Teams that is currently available
   Download Microsoft Teams

■For Mac OS

1. Sign out from Microsoft Teams.
2. In Finder, hold down the Option key and click [Move].
3. Click the [Library] folder, which appears directly under the Home folder.
4. Delete the following related folders.
   ・Application Support/Microsoft/Teams
   ・Application Support/com.microsoft.Teams
   ・Caches/com.microsoft.teams
   ・Caches/com.microsoft.teams.shiplt
   ・Preferences/com.microsoft.teams.plist
5. Uninstall the Teams desktop client.
   For details of how to uninstall the application, please refer to the following:
   https://support.apple.com/en-gb/HT202235
6. Access the following URL and reinstall Microsoft Teams.
   Download Microsoft Teams

You need to uninstall Teams and then process to clear the cache information. See below for details.
(Please conduct at your own risk.)

■ For Windows OS

Please sign out from the Microsoft Teams app before taking the following steps.

1. Uninstall Microsoft Teams
   ※ The procedure starting with uninstallation is guided as the Microsoft’s recommended method.
   1. Right-click the Windows icon at the bottom-left corner of the screen and open [Apps & Features].
   2. Uninstall the following two products from the Apps & Features list.
      ・ Microsoft Teams
      ・ Teams Machine Wide Installer
      ※ Click the product name and [Uninstall]. Try one at a time.
      ※ If you cannot find Teams Machine Wide Installer, follow the steps below after removing Microsoft Teams.
2. Clear the cache of Microsoft Teams
   1. Press and hold the Windows key, and then press the [R] key.
   2. When the [Run] dialog box appears, enter “%AppData%\Microsoft” in the [Open] field, and click [OK].
   3. Delete the [Teams] folder. ※ If you can’t, there may be some Office applications running such as Microsoft Teams, Outlook, Word, Excel, etc., which should all be quit.
   4. Similarly, press and hold the [R] key while holding down the Windows key, enter “%LocalAppData%\Microsoft” in the dialog box that appears, and click [OK].
   5. Delete the [Teams] folder.
   6. Reboot the PC.
3. Reinstall Microsoft Teams
   Access the following URL and install the latest version of Microsoft Teams that is currently available
   Download Microsoft Teams

■For Mac OS

1. Sign out from Microsoft Teams.
2. In Finder, hold down the Option key and click [Move].
3. Click the [Library] folder, which appears directly under the Home folder.
4. Delete the following related folders.
   ・Application Support/Microsoft/Teams
   ・Application Support/com.microsoft.Teams
   ・Caches/com.microsoft.teams
   ・Caches/com.microsoft.teams.shiplt
   ・Preferences/com.microsoft.teams.plist
5. Uninstall the Teams desktop client.
   For details of how to uninstall the application, please refer to the following:
   https://support.apple.com/en-gb/HT202235
6. Access the following URL and reinstall Microsoft Teams.
   Download Microsoft Teams