I have created a custom user field called Tester
I want the user picked in this field to receive a notification in Jira
People set as watchers with the eye button do get notifications
People set as assignee in the Assignee field do get notifications
People set as reporter in the Reporter field do get notifications
But people set as tester in the Tester field do not receive the notification

The scheme is assigned to the project and the user has enabled all notifications
What can we do?
Backup plan: set users from the custom tester field as watchers automatically - can I do this in automation or is it only for specific users not 'users from a custom field' ?