Librarian Villagers Disappearing

I have a trading hall filled with librarians. I had previously done the “turn to zombie, turn back to villager” process to get better trades. During this process, many of my zombie villagers went invisible (as per other issue logged), when they came back and were cured, I then had lots of them doing the flying out of their bed thing (as per other logged issue) and now they have disappeared. There is no way for them to get out of the trading station and no way for anything to get in, so they can’t have died. They just disappeared. Hoping someone can help as I’ve seemed to have consistent different issues in the past week or so. 

Thanks for your time.