I am having the same issue with bred villagers not giving a discount after being cured from the zombie state while naturally spawning villagers will give discounts after being cured.
Also, villagers from breeders who were zombified can not be placed into boats or minecarts. Once they are cured, they can again get into boats and minecarts.
This is on the Windows 10 version.
I have been unable to reproduce these conditions and mob spawns now seem to be good in the nether when the "owner/host" of the world is not in the Nether.