Xperia Z5

Not the first time it happens. And doesn't always happen but it's the second time. When I do some changes to the world (eg. Place some blocks) them leave the game. Then enter the world again. The game doesn't save some changes like some of the blocks or things I placed. Maybe I can't really explain the problem but take a look on the pictures. The first one shows a build I've made before I leave the game. The second shows the same build after I entered again. Notice some blocks and things has disappeared and got replaced by some blocks that were in the same places before I make the changes. (Like the game undoes some of my recent changes )..
And again is has happened earlier with a different world. The both worlds are made before 0.17.0