Manufacturing valuation not accurate

It appears that there is a problem in stock valuation(FIFO).
Suppose i have an Item1 manufactured, that requires a quantity of 10 pcs of Item2 (raw material).
I buy 6 pcs of Item2 from a supplier with a price of 3$/unit, and 6 pcs from another supplier, at a price of 4$/unit. After updating cost in BOM of Item2, the valuation is 35$.
After starting the work order for 1 piece of Item1, based on BOM, I make material transfer to WIP, a quantity of 10pcs of Item2. Using FIFO, it takes 6pcs at 3$, and 4 pcs at 4$. 6x3$+4x4$=34$.(correct)
The material transfer has an accounting ledger of 34$.
After that, material consumption is correct, at 34$.
But when I make the manufacturing stock entry, it calculates on BOM valuation, at 35$ (wrong)
So, total cost is 34$, but the value that enters on Finished goods warehouse is 35$.
I think that the manufacturing stock entry must be calculated not on BOM, but on consumtion cost.
Please correct me if I’m wrong.
ERPNext Version-12-develop

Reported here Manufacturing valuation not accurate! · Issue #20514 · frappe/erpnext · GitHub