What could be the error?
Product A Manufacture: BOM from A contains one product B
MO to produce 10 Products A -> replenishment to purchase 10 Products B -> PO confirmed & received -> MO confirmed & Done.

Stock location:

On hand quantity: 10 Product A and 0 product B
Available Quantity: 10 Product A and -10 product B

I received 10 B (vendor location -10) used 10 in production (production location +10) why the available quantity in the Stock Location could be negative?