Using the auto complete for JQL search on a user populates the username value which can be a UUID

Issue Summary

Where performing a JQL search using a user field, selecting a value from the auto-complete options will populate username.

In the case of newer users, for example those provisioned with SCIM this is a UUID and not human readable in a usable sence.

Steps to Reproduce

1. Provision a new user with SCIM.
2. Assign an issue to the new user.
3. Search for this user using JQL and type the display name of the user

    assignee = jira 

4. Then select this user from the autocomplete pop-up.
   

Expected Results

The best result would be that the auto populated value would be either display name.

Actual Results

The username is populated which going forward will be a UUID.

Notes

This is related to the work being done to facilitate: Say goodbye to usernames in Atlassian Cloud

Workaround

To workaround this avoid using the auto-complete option and type the users display name or email address in quotes like

assignee = "nero@jira.com"

assignee = "Nero Battlebeard Wolfgang"