Inventory Valuation Report and Cost Item

Summary

We have for the cost element No Recuperable one negative amount.

Content

We have a receipt 1215, we returned the ítem because this ítem was with tax and this item should not have tax. 

I'm attaching files where we see negative amount for tax in the unit cost. We want to know how the system calculate the -1.007,67857 amount.

Thanks. 

Regards, 

Carolina.