Villagers and iron golems incessantly disappear for no apparent reason

My village I have is relatively large, (around 20 villagers), has iron golems, and they are all able to move around the village as they please, as I have properly lit and built 4 block high walls around my village. They are regularly traded with and are very close to my main base, and so are loaded much of the time I play survival. As of writing this, they have all vanished including all three iron golems, apart from one fletcher villager. This is the third time this has happened, the first time being just after 1.16.0 was released, another in 1.17.20, and finally in the current update, 1.18.0. They are secured, and patch notes say this bug has been fixed many times, however it keeps happening to me. Please note that the three iron golems in the village disappeared too, and this bug has never occurred for any other mob before, either.

Thanks. Please fix!