Check the "EmployeeID" in User Profiles in CA, ensure it has values.
Navigate to User Profile Service Application -> Manage User properties, ensure the property has a mapping to import an AD attribute from the source data connection to this property.
Check the profile of the user, User Profile Service Application -> Manage User Profiles, see if it has value. If not, perform a full sync and see if it is updated.
Then, Check the "EmployeeID" in the User Information List. Check if it has values.
Navigate to the User Information List via http://siteurl/_layouts/15/people.aspx?MembershipGroupId=0
Settings -> List Settings
Display the "EmployeeID" and check the value.
If it does not have value in User Information List, run the following timer job to synchronize the User Profile user Data with user Information List
- User Profile to SharePoint Quick Sync
- User Profile to SharePoint Full Sync
Information about User Profiles and User Information List:
https://gallery.technet.microsoft.com/office/User-Information-List-in-8b420e8c