I found the zombie village and cured the villagers in there, but they won't trade. It also looks like they don't pick items or breed. They all look like farmers, but do not farm. 

Seed is: 10022018

Coordinates of the zombie village: 1520  72 -574 

Tested on the other seed with zombie village, the same thing happens.

Other zombie villagers spawned naturally or from zombie villager egg are cured normally and can be traded with.