I was working on an entirely survival world on my phone and ventured to gather clay in a nearby river. I then saved and exited my game while still in the river. About 5 minutes I reopened the game and entered the very same world. However, I found myself very very high in the sky only to land in an area that was entirely different from when I left. I then ventured to my last location in search of my items only to confirm that I hadn’t died in the same space that I left off at. I tried to recreate the event by going in water and saving and exiting but I came back in the same place normally.