Accessing Microsoft Teams Free using personal or organizational credentials
What exactly is the OS version of your Windows 11 installation? Teams might not work if Windows is missing the latest updates.
Uninstall any currently installed Teams app.
https://support.microsoft.com/en-us/teams/troubleshooting/uninstall-microsoft-teams
Install the latest Teams version using this installer site.
https://www.microsoft.com/en-us/microsoft-teams/download-app
Login to Teams using your Microsoft email address or legacy Skype Name.