Igloo Dungeon items spawned

In an Igloo, I looked for a dungeon and found one, but when I went downstairs, the brewing stand had a potion of weakness in the interface, (which is normal), as well as an extra potion as an item on the table next to it (floating, as when you throw out stuff from your inventory). The same problem occurred for the cactus plant next to it.\

Usually, there are no items loose in the dungeon, but now there's a copy of the potion and cactus spawning in the igloo.