Some employees not appearing on Global Search

Summary

When we look up a certain employee at our company, their profile doesn't appear in the Global Search

Content

EDIT: Problem was solved. It was an issue due to the different types of Leave. 

Hello,

Whenever we use Global Search to search for a certain person, they don't appear in the search. However, when we look them up in the Directory app, they appear with no issue. This employee is not a contractor and is a regular employee, so they should be appearing. The only difference is that this employee is on a Leave of Absence. But we can look up other employees on Leaves, so it shouldn't be an issue.