Minecraft wiki entry for Multiplayer, associated text: Once making the world multiplayer, some differences are noticeable, with one being that game mechanisms don't stop working if the player pauses the game. For example, if the player has items being smelted in a furnace, pressing ESC does not stop the smelting process. In Bedrock Edition, there is no difference as opening the menu in a singleplayer also doesn't pause the game.