Wendigo Claw bug

[bibaspes]

When i equip it, my shown attack power is 16, but i do 20 dmg, and if i equip item with STR bonus like miner belt, ATK goes up to 22 and shows real number and i do 22 dmg to monsters.

So it gives +11 ATK, and my dmg 11 more, than unarmed, but ATK stat in menu goes up only by +7