My world keeps being deleted, And restarted. This issue deleted all my progress.

My world keeps getting deleted. This Issue/Bug deleted all of my progress, and all it left me with is a world that hasn't been played. When my first survival world was deleted I thought it was because I logged out too quickly, But then I created another world and that got deleted after 3 months of play time. The last world that got deleted was the world I put A lot of progress in. Which is why i'm here. Please fix this issue, It ruins the fun of Minecraft