[Bug] Prisoner Boss Regenerates to Full Life When Companions Are Active

Builds/Setup:
Class: Infernalist

Companions: Infernal Hound + random Tamed Beast

Alternate character: Smith of Kitava (using Manifest Weapon)

Act: 4

Issue:
During the Prisoner boss fight, the boss regenerates back to full life once reduced to low life when companions are present. This prevents completion of the fight.

Steps to Reproduce:

Start the Prisoner boss fight with an Infernalist using at least one active companion (Infernal Hound or Tamed Beast).

Damage the boss until he reaches low life (after Ballista phase).

Observe: the boss regenerates rapidly back to full health while companions continue attacking.

Expected Behavior:
The Prisoner should remain at low life and be killable, regardless of whether companions are active.

Additional Notes:

Tested with companions active → boss regenerates indefinitely, cannot be killed.

Tested with companions deactivated → boss can be killed normally.

Behavior seems tied to companion attacks triggering unintended regeneration.

Can confirm this is still an issue, Boss is regenerating health off of minions during the 3rd phase.

Boss is healing during the Blood Explosion ability, while the minions are standing in the area of the ability.

At this point it is unbeatable by my character, minion build.

Bumping this, as this need more visibility. Disappointed that in the patch notes (0.3.0.c Hotfix 2), it didn't address this.

Note: I talked about this on the POE2 reddit, which can be seen here: https://www.reddit.com/r/PathOfExile2/comments/1nix8oh/the_prisoner_act_4_boss_is_practically_impossible/

Present method to win the boss: Press "P" to passive skill tree, which pauses the game, when Prisioner uses its attack. From there, unsummon all your creatures. Once attack is over, again use same strategy to re-summon all your creatures.

still happenining, i am on warrior totem build with the spirits and i cannot beat the boss no matter how i try to kill him. i use ballistas constantly and even though he is barely any life left he regens to full health every time and i die because im out of flask charges and cannot re kill him all the way down again. i cannot unsummon my spirits because they are part of my ascendency unless i go and undo those points but i will also lose a ton of damage making it even more difficult to kill the prisoner boss.

***EDIT***
i took off ancesteral spirits and even with just totems the boss regens full health then does the blood arua thing that i cant escape and kills me instantly. i have beaten the prisoner boss many times on other characters bu this is the first one that i hvae had totems or minions per say and i cant get past it :(

Even without companions, when I Ballista him, he still regenerates to full

Just remove the damn ballista mechanic..

Disabled minions to have less healing, do even less damage, have an even longer fucking boss fight and then despite using the ballista immediately it just heals back up to 70%. This isn't a skill check or even a gear check at this point, just remove this kind of extreme healing.

On farmer druid it becomes just rediculous, I don't know what's wrong with it butt I managed to get ihim to not regen HP only once the rest of the times I'm literally standing next to ballista within 0.5 sec I click on it once the prisoner is down and he still heals up the HP...

Build: Witch, minion build.
Poe2: .4
Having same issue. Can not progress past "The Prisoner" area boss. Boss continuously revives back to full health once reduced to low life regardless of bolistas'.

Jumping in here too, playing a Warbringer totem build - literally all my damage is totems. I have 5 totems and cannot time them for them to be not on the field when he uses the blood ability - generating full health every time. I cannot afford to respec my entire build just for one fight so I sat in global for 30 minutes asking someone to take pity on me, emptying my stash of chaos and exalts for the first person to put me out of my misery. I had been crushing the campaign until this screeching halt - NOT fun.

it does regenerate to full here too but i also noticed his hp pool get smaller each phase, fought him once but i'm pretty sure of that...
I'm not completely sure like i said i fought him once but if it's that the case:

3/4 hp first ballista --> back to full = 3/4 original hp pool
1/2 hp second ballista --> back to full = 1/2 original hp pool
1/4 hp third ballista ---> back to full = 1/4 original hp pool


I'm saying this because the last ballista i used he went back to full but his full hp pool was like 150k?
Like i said not 100% sure...