Playing the original SkyBlock 2.1:
Curing Zombie Villager (being fisher):
The villager, still being novice, is not becoming farmer or something else.
I placed and removed barrel, loom, compost, nothing happens.
He is sleeping in (my) bed and wandering, but not changing profession.
The world is attached.
Besides that, he does not work, does not harvest and replant crops and does not replenish his trades.
I loaded the world and found that the villager is a farmer,
[media]. Unless you are referring to another villager, I cannot reproduce.