Cast on Ignite with Demon Form

Hello i would like to know if its intended or not that i cant go into Demon form as soon as i have Cast on Ignite aura active (doesnt even give me any error why) but if i deactivate it and go into Demon form i can just activate it again and it works

is there a bug or is it not intended to use Demon form with Cast on Ignite at all?

Bump

do you have a support gem that costs spirit on demon form? cause if so the spirit doesnt get taken until you go into demonform