You'll have to check the employee's tax file declaration making sure you've entered the correct visa country code when working as a holidaymaker. Here's how to check:
Click on the Employees tab.
Click on the employee's name and go to Tax File Declaration.
Uncheck the Is approved working holiday maker, and then re-tick it. It will then ask you to update the employee's working holiday maker status and select the Visa country code of the employee.
Click on Save.
You can also check the following link below to further check the employee setup: