Minecraft preview saves not working

I was playing in a world on the preview iOS version. While in it, I was exploring when I got lost in the forest. I made a treehouse to stay alive I friended a wold blah blah blah. Then I saved and quit. When I reloaded, I went back to the house I got lost from, exactly where I saved last in that area. Next time it was normal. Then the next. Then the next time. And then the next time I reloaded into the area where it was bugged. I don't want that to happen for a 3rd time so could you please fix this?