Cured Villager does not have discount

In creative and my hardcore world I have cured multiple zombie villagers but they never seem to have a discount. I've tried giving a villager a mending book trade, but when I turn him into a zombie villager then cure him it doesn't have the same trade and there is no discount.

 

Searching on google :
Do cured villagers give discounts?
 
 
A newly-cured villager, if it had a profession prior to being zombified, offers a trading discount to the player who administered the cure.
the profession it received stayed the same after the cure but the trade wasn't discounted nor did it stay the same.