Notifications are shown in the user profile page in the front end of the site based on the access they have and the access the notification is set for.

For example "User Signup" and "Property Add" notifications are only for users who have admin access and "Property Confirmed" is only available for those having propertywizard access.

So if your users don't see some notifications in their profile page, first check their access in RPL and if they are supposed to see some notifications, grant them the proper access.