- Create an user with Jira version >= 8.9,
- Create a custom field with type "User Picker (multiple users)" and assign it to project screens
- Create a new issue and fill the User Picker field value with the username from step 1.
- Anonymize the user
Username in the issue history is changed to the user's anonymous username
Username in the issue history remains unchanged
Currently there is no known workaround for this behavior. A workaround will be added here when available