I was playing on my phone, no problems at all. I went adventuring in my world. Then, I had to stop playing, so I quit to title, and closed the app. Now, when I go to open that world, it reverts back to that point, whether I have played past it or not. Basically, it hasn't been saving ever since. I tried drowning, lava death, sleeping through the night, staying awake through the night, crafting something, quitting to title, closing the app, and all of that with and without WiFi. None of it works. All my other games save my data, so I don't think it is a problem with my phone. I know I have a lot of space available.

The picture shows where I spawn every time I open the world. Even when I move around, and play, when I stop and go to play later, it still spawns me here.