In large organizations, people come and go. People who have left have their user IDs disabled. The search screen will not let you entry the name of a user that is disabled. This is preventing us from finding content created by people who have left the organization. This is a major problem with replacement staff who attempt to pickup from where their predecessor left off.
As it stands now, when a user is disabled, they will not appear in the Contributor section of the search page. Since there have been previous requests to hide disabled users, it may be best to include a checkbox (or a toggle-switch) of some kind to include/exclude disabled users for the Contributor search.