Answer
Use Custom Leave Accruals only when the employer offers an additional leave type that is separate from statutory Annual Holidays, Sick Leave, and Alternative Holidays.
For statutory balances, use Leave Settings and Leave Entitlement Adjustments. For a custom entitlement, first make sure the company leave balance exists, then create the employee's custom accrual rule from the Custom Leave Accruals tab.
Do not use a custom accrual to force annual holidays or sick leave corrections. Add a manual adjustment to the statutory ledger instead.