Steps to reproduce

1. Make sure there are no villager workstation blocks nearby.
2. Spawn 2 zombie villagers.
3. Cure the zombie villagers.
4. Place 3 beds near the cured villagers.
5. Give them lots of food.

Expected result
The cured villagers enter love mode and spawn a child villager.

Actual result
The cured villagers never enter love mode.

Note: testing has found that cured zombie villagers are able to enter love mode only after they have claimed a workstation. This is not the case for normal villagers.

Original desciption
Zombie villagers that have been cured and are used to start a new village (player made) never breed, even if given more than enough food/beds. This does not affect naturally spawned/bred villagers.

I believe that this was caused by 1.12's change to Z. Villagers keeping their profession after being cured.

Attached photos are of two previously cured zombie villagers in a player-made village, note that cats have naturally spawned and that the villagers are properly linked to their beds as they sleep at night. (They have several stacks of food in their inventory.)