Missing users in autocomplete textboxes on several Confluence dialogs

• Login as admin
• Create a new user with developer role
• Create a project
• Click on the "Wiki" tab.
• Create a page
• Click on tools -> Page restrictions
• Type the new user's name in the textbox

Expected: Username to appear in the dropdown

Actual: No matches.

Note:

• This reproes for any page where user look up is present. For example, the Manage Watchers page.
• The people directory page is also missing the user, although I am not sure if the expectation is that it would appear here or not.