Custom Mob Spawners Not Working Without Cheats Turned On

When I give myself an empty(nbt data has its spawn id set to nothing) monster spawner without cheats enabled(using a command block of course) and I try and place it down it turns into a pig spawner, even though the nbt data of the block is telling it to have an empty spawn id. When I enable cheats on the world by turning on LAN and then place it down, it comes up as an empty spawner.