In the Production order feature the “Add non-inventory cost into production” button is very good but this has a flaw. This makes a faulty accounting entry. The expense is added to an expense account as credit which is incorrect. It should not increase the inventory asset but simply when required calculate the inventory cost but instead add the debit in expense account and add credit in either a payable account (supplier) or directly credited in cash/bank.
There is no issue with how it works currently. That non-inventory cost allocation is for you if you want to capitalize an expense.
So according to accounting principles it is working flawlessly.