Why is Sales Order issue txn distribution split by cost element? (R12.2.5)

While testing our new R12.2.5 environment (have not gone live yet), I find that Sales Order Issue transaction distiributions are split by cost element.

I was expecting to see TWO distribution lines only for the each transaction of type Sales Order Issue, one for DCOGS and the other for Inv Valuation in the following manner:

DR    DCOGS  (item cost) 

CR    INV         (item cost)

However, both the DCOGS and Inv Valuation have been split into two by cost elements Material Cost and Resource Cost (other costs do not exist).

ie, there are four distribution lines like this:

DR      DCOGS    (item material cost)