The world icons will be wrong frequently.

Here are three occasions that was discovered by me so far:

1. A world icon was abnormally displayed in front of another world.
2. After saving a world, the icon could not display. But when backed to the menu screen and click "Singleplayer", the world icon displayed!
3. A world icon can not be saved.

Among them, only the 2nd and 3rd occasion can I attach videos below. The 1st occasion is a probobility event (and it must be reproduced via opening a lot of worlds).