[1.2.1.4] no armor piercing on Redeemer of Malmouth

I’m not sure whether this issue is a bug but intended. The armor piercing on weapons have completely changed after some recent patch and it is now either 0% or 100%. The weapon “Redeemer of Malmouth” is a sword with pierce damage and +1 nightblade bonuses and it used to have some armor piercing in the past. It is rather counterintuitive for it not to have any armor piercing.

The Redemeer of Malmouth is a physical weapon first.