Cost Variance Difference between AA and CA

Dear All,

We are using JD Edwards Enterprise One 9.0.

Local Currency: LBP, Foreign Currency: USD

While creating new voucher match (P0411), and changing "For. Amount Matched" for an Item, the system creates a cost variance.

The Cost variance created in LBP (Local Currency) is different from the Foreign Cost Variance * exchange rate.

The Local Cost Variance is calculated based on "Local amount on PO" - "Local amount on Voucher"

(Basically the difference is generated from the difference of exchange and rounding between unit cost 4 decimals and extended 2 decimals)

Is there any setup to prevent this difference?

Thank you in Advance.