Shockwave not considered as a melee kill

I'm playing static strike with shockwave support and I allocated the node Righteous fury in the skill tree

Since shockwave support has a "Melee" tag and the skill is written "on Melee kill", I thought that it should work. But it's clearly not, I get the bonuses only when my beams or initial hit kill a monster. Is it intended to only work with melee main skills and not support, or is there a real issue their.

Anyway, thx for your work, the game is amazing