Hi there Lennyledoo,
You'll need to check and setup the Calculation Basis according to the employee's Pay Basis to ensure accurate leave accrual. The Calculation Basis for leave accrual depends on the Pay Basis of the employee, which can be either hourly or salary. For hourly employees, the calculation basis should be set to "Equals [x] Percent of." For salary employees, it should be set to "Equals [x] Hours per." If these settings weren't setup correctly, the Holiday Leave accrual wouldn't be calculated properly. You can also check this link for more information.
Best regards,
Doreen