I started a new world and I went to the underworld to fight the Wall of Flesh, but when I dropped the Guide's doll into the lava, it didn't summon the Wall of Flesh. I checked the map to see if the Guide is dead or something, but he isn't. I did it again and I stood near the lava, so it is easy to understand if it went into the lava, but nothing happened.
Can you guys explain what is going on and let me know if you experienced this as well?