Villagers won't restock after being turned to zombie

I have set up villagers in my server no different than I have before. I have set my server up no different than I have before yet I'm running into a bug where every time I turn them into a zombie villager and then cure them, they no longer restock their trades. Like i said I've set them up no differently than I have in the past. And I have their work blocks right in front of them. I cannot figure out what is causing this.