Ok, I meant that if you were to drag an item out of your inventory, then click "M" to open your map for example. That's what I heard, but after testing it I'm not sure. I can kinda understand it, since the map would be what you have selected and not the item?
I dragged a large hibiscus to a tail slot, and my friend had this glitch when selling meat to Tanja, so I don't think it has to do with the exact slot.