I had built up my spawn island, and had made a huge map wall on a nearby island. I had been out exploring and uncovering more maps, and my game glitched and there were holes in the map where I could see through the world. This had happened before and I had gotten knocked into the glitch and I had died and it said I "fell off the world" all of my stuff was gone, so when it happened earlier while playing I shut the game off and restarted. It took me back about 20 minutes in the game, but the glitches were gone. I started heading back to my spawn and noticed part of the island was completely  reverted back to as it was when I first started the world. My entire map wall was gone, along with a chest of all my duplicate maps, all my animals got caught in the glitch and we're gone, along with my first small house I build. The game had just reset entirely to how it was the very first time I was on it. Hours of uncovering maps, all gone. I'm currently in the bet 1.13.0.1