Hi,
I created a team-managed project named "XYZ". Then, I added a user picker custom field named "QA By" for all issue types in the project. I restricted it single user.
Now, when I go to the Filter>Advance Issue search, I can search by the "QA by" field. But when I select the "QA by" field, the "user selection dropdown" appears and it shows me suggestion of only 5 users. However, I have 15 active user in Jira.
I tried typing with different active user names excluding those 5 suggestion, but it shows "No Matches" 
Can anybody help in this regard? Thanks in Advance.