Hi Luis,
Unfortunately, there seems to be no option to auto dismiss or clear notifications in Windows 11. The only option similar to that is in Settings > Accessibility > Visual effects > Dismiss notifications after this amount of time, but it only controls how long each individual notification banner stays visible on screen**,** not stop the 'catch-up flood' notifications when you return to your PC.
As a workaround, you can click the Do Not Disturb icon in the notification panel before stepping away from your computer. This will keep notifications from popping up one by one when you return, and they’ll remain tucked away in the notification area as long as it stays enabled. If you usually step away at specific times, just set it to activate automatically during those periods in Settings > System > Notifications > Turn on do not disturb automatically.