[2022] In crusade combat, Channel Negative Energy doesn't heal my undead troops. Is that a bug or am I using it wrong?

The ability says it restores (Power x Power +5)d6 HP to all undead. I'm on a Lich run and my entire army is just skeletons, zombies and skeleton archers, yet when I use the ability, it drains energy from the general but doesn't heal any HP. I chose it specifically to be able to heal my troops, and it doesn't do that one thing.

Am I using it wrong, or is it bugged?