My friends and I recently opened a realm to start a new world. One of them was telling me how he spent an hour working on our house and when he left and logged back in later, it was reset back to before he started working on it. I brushed it off but today it just happened to me. I spent a good 2 hours working on a massive tower and was so happy to be finished. I logged off to get a snack, came back a few minutes later and logged back on to find that none of the progress I did was saved and was now reset. I logged out normally through the Minecraft menu so it should have saved, yet it wasn't. This is a massive issue as now, I have no idea what will be saved and what won't be saved.