Avoid showing notifications at startup in vaadin-app-layout

[frankrues]

I have recently migrated from version 3.0.0.beta5 to version 4.0.0. In my app, I do persist all notification in the database. In version 3.x when the notifications were created before the AppBarNotificationButton was added to the layout, the notification were not popping up.

Now in 4.0.0 the behaviour has changed, the created notifications are showing when the view is attached even they were created before the NotificationButton was added.

How can I suppress the notifications from showing at start-up?