Brutus' Brain not working properly

As the title already says Brutus's Brain does not seem to work in the Trial of the Sekhemas. I am using it on my skeletal cleric and the cleric definitely takes damage and dies.
Bug report number is 3.557.518.641 (man, I really hope they didn't start at 1 xD)

Edit: it doesn't work correctly in maps either. the cleric is taking damage even with the brain, re-summoning the cleric didn't help either