Unable to assign certain user as a Component Lead

Summary

It's not possible to edit the Component Lead and assign it to specific users. Below error message is shown:

• The user "username" does not exist.
  

Steps to Reproduce

1. Have a project and some Components (Component One and Two)
2. Have a user and rename it (i.e from John to A)
3. Assign it to users (A: affected user, B: not affected)
4. Edit both components

Current Result

1. Component One with A as the Component Lead shows grey avatar icon instead of their uploaded avatar and the old username
   • 
2. Component Two with B as the Component Lead shows the uploaded avatar but when I assign A as the new Component Lead, below error is displayed.
   • 

Expected Result

1. Component One with A as the Component Lead shows their uploaded avatar and the new username
2. Able to assign A as the new Component Lead in Component Two.

Notes

Users can still create a new component with the affected users (A) as the Component Lead, but not editing the existing one.

Workaround

Update the component lead using REST API:

curl -D- -u username:password -X PUT --data {see below} -H "Content-Type: application/json" https://instance.atlassian.net/rest/api/2/component/<component_ID>

{
"leadUserName": "username"
}

Tips

In order to quickly gather components for the project via REST API:

1. Grab Project ID by running a GET

   https://<instance>.atlassian.net/rest/api/2/project/
   

2. Insert ProjectID into this GET

   https://<instance>.atlassian.net/rest/api/2/project/<ProjectID>/
   

A list of all the current components to the project will appear.