During confirmation if the stock is in the right bin(control cycle) then system will consume from there using the MvT 261. Check the reservation whether the Storage type / Storage bin are getting stamped correctly or not during Production order creation.
is the quantity in 914 is -ve or +ve Quant
Normal process flow is
You transfer the stock to PSA
and upon confirmation system consume the stock from the storage bin specified in control cycle (depend which transaction you are using)
if the stock is not in right bin then system create a negative quant in 914 storage type