Not updated EpiCurrencyConver

There is EpiCurrencyConver control , at the Opportunity/QuoteEntry -> Lines form. In case if the selected customer has a constant discount it should be shown it to 2 discount selected controls, numDiscPct or currDiscountAmount . The numDiscPct shows percentages, but currDiscountAmount shows exact money.
Base at these controls currTotal will be different from simple UnitPrice. At the time, when there are only percentages discount specified but not real money currDiscountAmount , the Total after discount is not updating. The total just simply shows UnitPrice, no matter how many percentages this customer has.
This situation is happening not every time, but constantly after FormLoad, and after manually modified % discount value.
This miscondauction begins after EPICOR version update to ERP10.1.600.0.
Everything worked perfect at the previous EPICOR version.
Does anyone facing the same issue? Please share any related information.