Cannot change villager profession

So I am curing zombie villagers in hopes to make a librarian.

Here’s my process…

1. I start off with a lit up room for the zombie villager with just a bed in it, with no workstation nearby.
2. I find a zombie villager, making it follow me into that said room I built with just a bed.
3. I throw a splash potion of weakness and give it a golden apple
4. The zombie villager is now cured, but defaults to a tool smith – even with no workstations around or nearby his little room
5. As there is no current workstation, I put down a lecturer next to the villager in hopes to turn him into a librarian from tool smith, but nothing happens. He remains as a tool smith.

I have tried to do the above on 3 different zombie villagers. All with separate rooms. But all of them defaults to tool smiths.

I watched tutorials and you can change the villager’s profession by destroying their current workstation and putting down a new one to reflect the required profession.

So this has raised the below questions –

1. Why do all the zombie villagers I cure always default to tool smiths even if there are no workstations nearby?
2. How can I change one into a librarian if they didn’t have a workstation in the first place when I cured a zombie villager?

I’m playing version 1.14 on the Xbox One.