Check this comment at Github: https://github.com/3scale/porta/pull/4080#discussion_r2108694481

The UI distributes the notifications among different categories. Each category can be enabled or disabled based on some conditions. For instance, :service_plan category is enabled only when the account enabled service plans from Audience -> Accounts -> Settings -> Usage rules.

When a category is disabled, the UI doesn't show it in the web form. If the user updates the preferences, notifications belonging to disabled categories are disabled.

When the user has a notification enabled but then the category gets disabled by changes in the account, the notification continues to be enabled until the user updates the preferences from the UI. This leads to the user receiving notifications about disabled features like service plans.

Notifications should only be sent when they belong to an enabled category.