There is a bug with breeding villagers. Usually when villagers breed the new baby villager has both a class and a trade inventory once they grow up.

but when they breed they baby villager is without a class, and when they grow up they cannot be traded with, (Similar to the nitwit but without the nitwit skin.)

I don't know if it affects them, but the biome is the Tundra village (New village)

Steps to Reproduce:
 Simply recreate a villager spawn trap. (a villager trapped in a maze of doors) then simply give food to the other villagers.

in the image the bad villager is in the crosshairs while the good villager is to the right