Delegate is not able to create expense Report

Summary:

Employee delegated to one User to create expense report. when user trying to create expense report, they are getting error message that 'he is not defined as employee'. PFB the screenshot.

When the person (User) is not an employee, how come Employee able to delegate him to create expense Report ? is this bug in oracle ?

Content (please ensure you mask any confidential information):

NA

Version (include the version you are using, if applicable):

25A

Code Snippet (add any code snippets that support your topic, if applicable):