Funds Accrual Engine not calculating retroactive Adjustment for volume offers

Hi,

I defined cumulative volume offer with retroactive flag on. and discount rules as followed:

0 to 10 get 10%

10 to 9999 get 20 %

Enter sales order with Qty 8 units system calculate accrual discount 10 % and running Funds Accrual Engine modify budget utilized and earned amount with the value of unit price * 10 %  * 8

Enter anther sales order with Qty 8 units system calculate accrual discount 10 % and running Funds Accrual Engine increment budget utilized and earned amount with the value of unit price * 10 % * 8

I was expecting that request should calculate budget utilized and earned amount as 20% * unit price for 16 unit

Is there is any other request to run to calculate the retroactive adjustments