Halfslab Blockbug

If you copy any of the Double slab blocks they become only two other blocks. All wooden double slabs becomes "Oak wood Planks/double slabs" and all stonetype blocks becomes "double Stone slab".
Also "double sandstone slab" becomes a "half sandstone slab" on the hotbar but becomes double stoneslab when placed. The other double slabs act correctly on hotbar. Check Attached image.