Invocated Echoes notable doesn't provide any Energy refund (does nothing)

Arc always costs 22% energy to trigger with Spellslinger invocation, Invocated Echoes notable never triggers to provide 50% energy refund. The skill menu doesn't even display chance for refund.

Both Energise notable and Energy Retention support gem provide 35% and 25% chance for energy refund respectively and they are properly displayed in the skills panel, these work fine.

I found the same issue on Spellslinger. The half energy never triggered when I tested. The skill panel does not display the description about the half energy consumption either.

This issue still seems to be lingering as of Fate of the Vaal. Would really like for this passive to work.

I've been using this notable on a Feral Invocation setup, strangely it works there even though I am triggering attacks rather than spells.
I don't know if this is how all invocations interact with this, but when it procs, I get 2x as many triggers. I guess making each "cast" cost half as much energy just allows for more casts per invocation.