This has happened to a couple of people within my group/guild.

I got a furnishing item drop from Scalecaller, I forgot exactly what the furnishing item was called but it was a group of very large mushrooms. Anyway, I placed it in my house, didn't think it fit there and a friend of mine asked if they could have it for their house. I agreed and traded it over to them. They teleported to their house and tried to place it. However, they could not find it in their inventory at all. They couldn't find it in the furnishing menu nor could they find it in their actual player inventory.

This also happened with another player too. But we all thought that particular player was either lying or just didn't know how to do it. But since it happened a second time, we know its an actually glitch. Both items were from the same dungeon and they were both giant mushrooms.