Villagers seem to be disappearing without a trace in the new update.
I had two separate villager pens with several hundred villagers and a separate one with just Librarians. Encased in glass with no exits. They seem to have vanished without a trace. I moved ten of them into yet another pen, a single block with just a piece of glass above them.
Those are all gone as well after checking it.
No raids have occurred in any of these places.
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Sounds like MC-150170, resolving as a duplicate
I have this same exact problem. I have a villager breeder then the babies are carried off to another room. Every time I go back, some are missing.