When a new flat world is created with the same preset as the one you just exited the entities get transfered

When I exited a world that was created with the Redstone Ready preset and imidiatly created a new one with the same preset the entities I had on the last map was transfered to the newly genereted world.

The entities that were effected were paintings and Item frames. The Item frames kept all there data.

Both world had structures off

The entities did not update automaticly like they do when you break the block there on

As seen on the picture Theres also some strange thing that I cant find what it is.