A quest item in Diablo 2 Resurrected (the Headpiece that you combine with Horadric Staff in order to enter in to Duriel’s lair) doesn’t drop when I open the chest in Maggot Lair. I did it many times, but nothing has dropped. There is nothing in my inventory, personal stash or Cube. Even if I close the game completely and re-enter, still nothing.
You don’t get the Amulet of the Viper from the Maggot Lair. Do you already have the Staff of Kings ?
You get the Amulet of the Viper from the Claw Viper Temple Level 2.