While many have said, even some devs I know, that the styx dragon boss is an outdated area that needs some updating, from the dragon flying and landing at the top of the ramp such that you cannot actually hit it without jankily trying to sneak past it, there is one thing I've begun to notice when I do runs there.
There is a small area that can overlook the dragon on the southern area of the map, and not once, not twice, but three times now I have noticed the dragon was lured to that area and was still alive, the devils in the area still alive, but the chests all unlocked and fully looted. It appears people can lure the dragon up there, sneak past all the devils, and scot-free loot its little hoard because the dragon flies up to the area but is large enough that if you run away and stealth it won't follow. Likewise, this doesn't appear to be a case of someone having come before and the devils respawning as there was no duplicate boss spawn.
This likewise isn't really a bug as it is working as intended, if an abuse. But the fact of fighting through the whole hoard of devils only to see the boss was lured away and the chests full emptied is annoying to say the least.