Selected singleplayer world is unselected on screen resize

When a singleplayer world is selected and the Minecraft window size is changed, it unselects the world.

How to reproduce:

1. Navigate to the Singleplayer menu.

2. Select a world by clicking on it.

3. Resize the game's window.

Expected result:

The world would remain selected.

Observed result:

The world is unselected.