Every time I exit the game, my sim gets deleted from the world.

So, I’ve tried this on two separate worlds with two different sims. The first sim (Meredith) disappeared while pregnant after I saved and left the game. Then I just readded her from the bin and started over. Then, after she got pregnant again and had the baby, I saved and exited the game. When I came back, only the toddler and pets were left in the game. I tried everything, resetting through NRAAS included. She wansnt anywhere except the family tree, wherein she had no photo and only had her name. So I decided that Dave must have been corrupt and created a new game, with a new sim, in a different town.  Well last night I saved and left the game, and came back only to find this sim was deleted as well. And her only existence is in the bin as a brand new sim. I built up a lot of her skills and don’t want to start over, she also fell in love with a firefighter so seems to no longer be in the game either (they were not in the same household) what is happening and what can I do? And both sims did show up on the save screen, it’s just when I load in they’re gone!