Why is it showing "No results found" when I try to select a Subject Category or Area of Tutoring?

Why is it showing "No results found" when I try to select a Subject Category or Area of Tutoring?

The fields Level, Subject Category, and Area(s) of Tutoring were designed to be filled out in order:
  1. Select one or more Levels
  2. Select one or more Subject Categories
  3. Select one or more Area(s) of Tutoring