IPC overwriteConditionValue doesn't update CRM condition value

Hi experts

I'm replicating a new custom ECC pricing formula in CRM.

No problems with others formulas, but with this new one, i'm not able to update the condition value in CRM.

The condition is a discount condition, and following oss note 80183, i've implemented my formula to round the value.

The problem is that, even if the java formula returns correctly the value rounded, CRM dosn't update the condition value (not the condition rate) with this value.

i've even tried this code:

pricingCondition.setInactive(PricingCustomizingConstants.InactiveFlag.INACTIVE_DUE_TO_ERROR); 

return new BigDecimal("-990");

CRM correctly deactivate the condition and update the old value with -990.

BUT

whit this code

return new BigDecimal("-990");

CRM keep the old condition value and doesn't update the condition with -990..

I really understand what's going wrong. Anybody can help me?

Best regards

Marco