Deadbeat123, only unrestricted secondary users have access to the notification preference page. If you cannot view the page, that mean you are a secondary user.
Hi Deadbeat123, thanks for the feedback. We have looked into this issue more and have been informed that while the Notifications Center is viewable to all eligible (primary and unrestricted secondary) users, Notifications Preferences should only be accessible to the primary user. I confirmed that the team is working to fix this experience.