(this has been reported, just adding here for reference)
NPCs at Camp of the Castaways on Siptah (TeleportPlayer 1566576.652941 -123016.139481 -19887.50561) start with (eg) 450 HP, but if hit this immediately becomes 99,999 HP and they stop taking any damage, becoming invincible. If the player is alone, they also do not aggro. If the player has a follower, then the NPCs do aggro on the follower, but still remain invincible, so will kill any follower.
