No email is sent/received when you enable the watching of a location

Preconditions: Have the mail sending configured.
Steps to reproduce:

1. Enable the feature in properties "notifications.watchedEntities.enabled = true"
2. As a simple user (with an email address) select to Watch a page or a page + children, under Notifications
3. Log in as a different user or Admin
4. Create / Update / Delete a/some pages under the watched space/page
5. As Admin go to Scheduler and trigger the notifications eg. Daily by default

Expected results: Email is sent to the user - "When you enable the watching of a location, you enable both the notifications in the menu and by email."

Actual results: No email is sent, notifications only appear in the list. No error message in the console.
Tested with MySQL and default Hyper.