Cost issue in part recovery on depot repair technician portal wip job

Below is our issue and trying to find a solution. Any help on this is appreciated

When we are doing - ve quantity issue which is a kind of WIP Return Transaction, then Technical Portal is performing following Accounting -

Part's cost is $104 is the layered cost which FIFO is returning to Oracle internally. We are using FIFO costing.

Device's cost is $0

Below are the accounting entries happening -

Ending Balance in WIP account = $500

After Part is issued then

Cr Inventory A/C by $104

Dr WIP A/C by $104

Now ending balance in WIP account (Trial Balance report in GL) = $604

After we recoverd the defective part