The Vanishing Alerts
Windows 11 centralizes all your app alerts, emails, and system messages into the Notification Center (accessed by clicking the date/time in the bottom right corner). However, to prevent this panel from becoming an endlessly long, cluttered list, Windows imposes strict limits. By default, the system will only hold a certain number of notifications per app, and it will automatically delete older notifications as new ones arrive. Furthermore, some app notifications are designed to automatically clear themselves after you unlock your PC or open the associated program. If you rely on the Notification Center as a pseudo to-do list, this automatic deletion means you will silently miss important reminders.
Prioritizing Critical Apps
While you cannot stop Windows 11 from ever clearing the Notification Center entirely, you can explicitly configure it to hold onto notifications from your most vital applications for much longer, stopping them from being automatically pushed out by trivial alerts.
Press the Windows key + I to open the Settings app. In the left-hand navigation sidebar, click on System, and then select Notifications in the main panel. Scroll down to the list of individual apps. Click directly on the name of a critical app (like Mail or Slack), not just its toggle switch. This opens the detailed notification settings for that specific program. Look at the bottom of this page for the Priority of notifications in notification center setting. Change this from “Normal” to High or Top. Notifications from this app will now be pinned to the top of the list and will be immune to being automatically pushed out and deleted by the influx of standard, low-priority alerts from other programs.