Stat Amount is not showing negative amount after invoice distribution reversal

Recently, we upgraded to R12. After the upgrade, we noticed some issue in the invoice distribution reversal. When we reverse an invoice distribution, the distribution amount is becoming negative, but the stat amount is not showing negative amount. It is still showing positive amount, our users have to manually change it to negative amount.

Why the system is not automatically calculating the negative stat amount, does anyone face this issue? Please let me know.

Thanks,

Jagan