Baby Villagers Can't Get A Job After Growing Up

Hey Mojang,

My name is Jacob,

So I  was getting villagers to breed so I could get more and then the baby villager that got made grew up and I couldn't get him to become anything I tried so I tried a Lectern, composer, stonecutter and loom.

Can you please fix this so I can get the Master Trader achievement I have been working on.