Villagers mysteriously disappearing

After waking up all my villagers, except for one, had all disappeared. I had over 20 max villagers in my breeder, and they all disappeared without a trace, after looking through 2 or 3 completely new villages, they too didnt have any villagers, but full chests, cats, and iron golems. the only villager that survived was a farmer that had been traded with in a 1x1 closing. we tried everything, to fix from what others said online, but we couldn't do anything