Save bug

Hi !

I have a very bad bug in minecraft, my save is corrupt.

When i play, i save and when i return in my world, sometimes, blocks placed before my backup desappears ... 😞 Same in all my save, survival or creative, login or not. But my inventory don't change!! I think it's not all of chunk who are reloaded (look at the picture)

Sometimes blocks reappears if i quit and return, and quit .....

It's very boring because i can't play normally.

I'm sorry if my english is very bad because i'm french ^^

Bye !