Prism of Belief does not increase level of Armour Piercing Rounds

Prism of Belief does not increase level of Armour Piercing Rounds.

Unequipping, equipping, changing zone, reloading does not help.

Tooltip shoes nothing so does the mana consumption which should indicate that the jewel is working.

I just came to report the same thing, super disappointing, was so exited about my +3 armour breaking skill :((