Android Furnace disappeared

[jameskuyper]

My son set up his furnace next to his bed, ignoring all issues of fire safety :-). While standing in his bed, he collected a copper bar from the furnace, and it disappeared. He says there was a brief animation involving some black dots, similar to the one you get when something disappears due to being mined. Is this supposed to happen? If so, why?

 

[Ereo]

When you hit it with a pick axe it gets dislodged. Usually it will pop into your inventory, but if his was full it might have fallen to the ground. Stuff on the ground can disappear when you leave the screen. In the house stuff can also jump into the void around it which makes it hard to pick up without magnet rings. Or maybe it fell under the bed and he didn't see it.