Hi Helga,
As far as i understand you have s show page activity in your Login Microflow and you show there the PopUp and the Homepage.
Now when the User is already signed in, the popup should not be visible when going to HomePage.
If so, one solution would be just to show the homepage without the PopUp.
If you want that the PopUp isnt there after he login again then you have to set a boolean like "readNotification" and if true, dont show the PopUp
Hope this Helps,