Replica Dragonfang's Flight Onyx Amulet

My Replica Dragonfang's Flight
Onyx Amulet has an explicit unique modifier stating the following:

+3 Level to all Gems

Once equiped the levels of my gems do not increase or reseve any benifit.
Tried the same amulet with other skills and seamed to work fine.

Image: https://imgur.com/a/FU9LCMQ

Bug Report ID: #311,654,984

this item should not be exist look like bugged item. Searching similar in trade say the game explicit line is elemental resistance.