Random deaths in survival worlds

I saved my survival world and everything was fine. A couple hours later, I rejoined and it took a long while to open the world. Once it opened, there was a message: “You died!”. I made a copy of the world and switched to creative to locate the items and to get them in the original survival world. But it turns out both of the worlds were switched to creative and I deleted both of them. All of that because worlds take minutes to load. And that’s probably how I died. This bug must be fixed, because many people may lose their inventory items in their survival worlds if they have left the world in an unsafe location.

How to reproduce the bug:

1)Create a world

2) Leave

3) Rejoin

 

Normally, the world should be paused before you enter and things shouldn’t be moving while the world is loading.