Villagers despawn when Game crashes.

Everytime the Game crashes ( I don't know why it does), villagers despawn when I'm in my trading hall. Once I also put down a shulkerbox with stuff to sell and when I was back playing it just disappeared. This is quite annoying because I already lost  four mending villagers    XD. I started trading in my world after 1.16 so I don't know if it happens before. I do realize lots of people Reported this bug but I haven't seen one where it's just when it crashes. Thank you for your time and effort in making the game more playable.