A question about Product Costing

Hi, guys,

I converted 2 production orders from a same sales order, each production order adopts 1 different production version separately, the 2 production versions are quite different due to different routings...

The situation I found was, whichever production order I did goods-receive FIRST, the product cost was fixed, the other production order would use the same product cost of the 1st production order despite a different production version was adopted already.

Our production mode is Make-To-Order.

Could anyone tell me the reason? Thanks.

Michael