Is Amazon Fulfillment Centre postcode incorrect for BHX3 Daventry?

Hey guys, iv been having parcels returned which are on route to FC BHX3 Daventry

these are Dangerous goods, so we have to use our own courier, all of which have failed.

i noticed that the postcode on the small amazon box label is NN11 8PQ

but the google page for the depot shows NN11 8QL

going to try sending it to the second postcode, but wondered if amazon have made an error?