Firstly, i have the One Plus 3, Android phone.

Whenever I load in to the survival world, it would take way longer time then it should to generated the world. After the world is generated, you will spawn at the world spawn point, with no inventory. This includes Armor, and the inventory itself.

Steps to Repeat whats happening

1. Open Minecraft app
2. Click play, and chose the world that you have loaded previously(particularly a survival world)
3.You would know, if its going to happen, when it takes a unusual time to generate the world.
4. Once loaded into the world, if you see your inventory empty, that means you've did it