A bunch of my world has respawned/reset after updating

Last week, my xbox told me I had to update my minecraft world to play. I updated it, and when I opened my world a ton of stuff had either despawned, or was halfway built. I was still holding all the items I had been holding when I had previously played, but other things like chests full of items had completely disappeared. I had built a lighthouse about a month ago, and when I checked the bottom half had entirely vanished, leaving the top half floating in mid air. A bunch of other things happened like this in my game as well. I tried deleting and redownloading the game onto my xbox, but nothing changed. I don't know what else to do. Any help would be greatly appreciated!