The bug
When using light_dirt_background.png and options_background.png are transparent in a resource pack, the world selection in singleplayer is not shown correctly. When there are more enough worlds to extend further down,
scrolling up and down will make the text will stack on top of itself. Any menus opened on top of the world selection will become very visually cluttered as the previous screen is not removed.
How to reproduce
Download the attached resource pack
Enable it
Confirmed for 1.13.1.