Empyrean Weapon Effect doesn't work with Harlequin Weapon (on Tremor Rod)

Basically everything is in the title.
The empyrean weapon effect looks usually great on 2h-weapons. Unfortunately it doesn't work with harlequin weapon skin.
Other weapon effects seem to be used only on 50% of the harlequin weapon skin if it's applied to a 2h weapon.

Short video:
https://i.imgur.com/9MjvKs4.mp4

the same thing happen with the ringmaster weapon skin(the wand version) and assassin weapon effect