This may occur if an earnings code is used to track values other than hours worked.
Duplicating hours in payroll data entry to add additional pay.

Use earnings codes to differentiate different job tasks rates.

Do not use multple rates for the normal payrate * hours AND an additional earnings code for the Additional payrate for each task. This doubles hours.

Check the box in earnings code maintenance for any earnings codes you want to exclude from the ACA reports. This means you cannot duplicate hours in payroll data entry as those will be included.