Villagers are not changing professions after their career block has been destroyed

When you destroy a block that defines a Villager's profession, it is suppose to cause the Villager to lose their overlay until there is another career defining block present, in which the Villager will change jobs to match the block. 

However, if you try to do this currently, the Villager will still remain as that profession, and will not change jobs. Despite the fact that the Villager is a Novice and hasn't been traded with, they will still not become unemployed.