Autoexertion + General's Cry + Bosses = No

It just doesn't cast on any boss. Doesn't matter if it's a unique mob outside somewhere, or I have to enter a specific boss arena. If their name is written in that gold text, Autoexertion does not cast General's Cry.

It works everywhere else. It's hard to tell at times, but it might also work if said boss has adds (because the adds trigger the cast or something???)

To be VERY clear on what I'm doing, here are the following notes to my build:

Chieftain (level 52)
Sione, Sun's Roar Ascendancy passive
Using Two-handed Axes
Sunder of Earthbreaking + Autoexertion + General's Cry + Added Fire Damage

Would be great if ANY of the companies that make these ARPGs actually had working builds outside of what Streamers showcase.... Just came from Diablo 4, was looking for something more refined in PoE and get this bs on the first build I decide to make.

Why is it always casting as I'm walking along roads then? Seems odd that it would work without corpses constantly until I reach a boss. I just figured that my Ascendancy was bypassing that part of it as well.

Regardless, thanks for the answer.