All Page notifications are cleared from the list when enabling Blog notifications and vice versa

Preconditions: Have the blog app installed
Steps to reproduce:

1. Log in as a user and enable the Pages Notification (email not needed)
2. Log in as another user/admin
3. Create / update / delete pages
4. Log in with the first user again
5. Observe the Notifications list
6. Click on Notifications Settings
7. Enable the Blog notifications
8. Refresh the page

Actual results: After enabling the blog notifications and refreshing the page all the previous notifications disappear.
The same thing happens when enabling the Blog notifications first and then the Page notifications.