In EIOBoard Web, if you are unable to locate some users under Admin>Users, it’s possible the users are being filtered out by the search parameters which can be accessed here.
There are filters for UserType, Group, Locations, Security Groups. There is also a checkbox that if enabled will allow the application to display Disabled Users.
If you notice that users who have signed in on the Kiosk or through self check in do not appear in the Users area of the admin, User Type is most likely the culprit. You may be searching for Staff when the signed in persons are actually Visitors.