Why does an Item standard cost change when Routing Line - Unit Cost Per change?

Goruck

Hi there,

We use standard cost for all inventory.

The strange thing is that whenever there is a change in the ‘Unit Cost Per' of the routing line then the standard cost (Rolled-up Subcontracted Cost) changes as well right away.

Is there way to prevent this from happening so the standard cost stays static?

Thank you!
Rudy