Lioneye's fall jewel double stacking

Hi, I was looking for a place to use lioneye's fall on my build and realised that all 2hand melee damage nodes had a line with reduced damage for 2hand melee, and 3 sperate lines for bow attack, the two normal ones, phys damage and ailment damage on hit, with an additional damage and ailment damage on hit, giving twice the bonus intended on the node.

I did some test with a respected character in standard that had only two jewel sockets and the stat nodes to get to those sockets. Then I put one point in the Two Handed Melee Damage node under Destroyer and the Axe Damage node near the evasion exterior cluster under the duelist starting point.

By moving the Lioneye's fall jewel from one location to the other I realised that even tho it says reduced damage it doesn't show on the tooltip for my axe attack and both node provide the same increase in dps for an axe, but the two hand node was indeed granting twice the bonus to my bow attack on the tooltip.

I don't know how to test the actual damage done to monsters in this game.
Is it a visual bug, does it actually double stack, is it intended to work that way, is it safe to use this jewel in my build or should I expect this to get fixed soon?