I recently acquired a Blackjack Panga that came with a leather pouch type sheath. It's evident that the sheath was (sort of) fitted to the knife, but the knife is very loose in the sheath. It slides into and out of the sheath with very little (almost no) friction. The sheath will not retain the knife if it's turned upside down (i.e., gravity is the only force securing the knife in it's sheath, if that makes sense). Is this normal for this model? I'm accustomed to pouch type sheaths holding onto knives more securely.