Champions respawning to full health in fight
It happens when you move to far away from where the boss originally spawns,it can be buggy though and think they should just increase the range of this on certain bosses.
You’re lucky. I wore him down 10 times, just to see the reset, before heading to the trusty old Google and finding out I need to drag him back to the nearby camp. :P
The spider boss, Gargantula, is supposed to go invulnerable, spawn a lot of baby spiders and heal up. It’s part of the boss mechanic. It happens 4 times I think and if I’m not mistaken, killing the baby spiders fast is key to not letting her heal up all the way.
Aside from the spider boss mechanic, I did not pull any of the bosses from their current locations and they reset their health. At first I thought it might have been related to stealthing triggering this as my character was a thief, but that did not have any impact on it. I can assure you that when i fought veteran romke i did not move at all from his spawn point and he reset multiple times.