assignees are not available in JIRA users list

[Sivarama Krishna K]

HI,

I am using the JIRA users list from two direcotries.

When I create user id manually with local jira user, we are able to assign to the right user. 

And the same is reflected in JIRA Database.

But when a user is created automatically using Active Directory, user name is coming properly. But while assigning, assignee is coming as JIRAUSER156007.

What is the issue and how to fix it.