Everything I build disappears

So I just downloaded the game onto this device all was going well. I created a world in survival and began playing I managed to build a decent sized structure, but was very upset to discover that everything that I had changed in the world was gone. I still had what was in my inventory, but all modifications and chest inventory were gone. Frustrated, I started over. Again, building a decent sized structure, the later that day, upon reopening the app the same thing happened. I thought, okay maybe it’s just this particular world, so I created a brand new file and got to playing, but the next morning, everything was gone.... again. I do have to say that I am extremely frustrated, and that this is a major glitch that makes the game basically not enjoyable to play. I hope that it will be resolved swiftly.