- Click your user profile found at the top right corner of the Teams window and choose Settings.
2. In the Settings window, choose Notifications on the left. Under Teams and channels, click the Custom box to see all the notification settings for Teams.
3. Change the settings to say Banner and feed for your mentions, replies and reactions.
4. Restart MS Teams by closing the app and opening it up again.
Reference article: https://www.onmsft.com/how-to/common-microsoft-teams-problems-how-to-fix
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