Unit Cost Changed In Generate PO (P5543060) Menu When Button OK Clicked

Hi Experts,

Here is the step :

1. Open Generate PO menu(P5543060 W5543060B)
2. Double klik 1 order to generate
3. In Order Release menu (P5543060 W5543060A)
4. Change the supplier code (valas currency)
5. Change the unit cost (let's say, from 999 to 10)
6. Click OK
7. The warning or error notification will show, but why the unit cost field changed from 10 to 999?
8. Users should change the unit cost value again!

Please tell me why

Sincerely,

Oviedityanto

EnterpriseOne Tools Release: 9.1.5