Country value not exist from external career site

Getting error message “The Country field is required” when applying for a job through the external career site
No error appears when creating a new person for the country Cambodia.

Step1 My Client Groups> New Person>>Hire an Employee
Enter the below details and click on next
Legal Employer : WSGO CAMBODIA CO., LTD.

Step2 Country Cambodia is populating with out any issues in Home Address Screen

Step3
Created the job requisition “Dummy2 Office Manager” under the same legal employer established in Step 1.

Step4
Logged in as an applicant through the external career site.

Step5
I’m unable to add the Cambodia country.