I was working on an article in the Game of Tomes world when I got randomly switched to my Caelum Prime world. It happened twice in less the 24 hours.
The first time I was trying to link an article in the article I was working on. The second time I was trying to set the parent category. I didn't touch either of the buttons to change worlds.
This has been due to developer troubleshooting your account due to other issues you reported.