Why won’t Brutal Axe die?

Recently when I’m in epic epic dungeon, my heroes periodically run into a Brutal Axe they can’t kill. His health bar drops to empty, jumps back to full, rinse and repeat until the right times out. And yet when my same heroes refight the same exact battle, they win in seconds. This happens sometimes 2-3 times or more per floor.

What am I doing wrong??

He’s meant to resurrect 3x per fight - any more than that and there’s problem

Based on what I see, it seems like he is resurrecting more than 3 times, and there is a problem.

I don’t see any way an empress, cultist, llama, and short stack at gold 3 rarity can’t finish off a brutal axe in 1 minute and 14 seconds (screenshot shows 16 seconds left and battles are 1 minute 30 seconds max), if he only revived 3x.

Unless he has a warlock stack on auto that he keeps stopping axe with…

Even still though