Despawning of villagers and named npc's

My entire villager trading hall of 20 villagers despawned. Each one had been traded with, linked to a bed and a workstation and had been cured multiple times. Additionally, my 2 named zombies, both named with a name tag, and a minecart with chest for my auto farm also despawned. All of these were in the same proximity to each other. Very frustrating as a lot of time and effort has been lost.