When you start a mission in the Eden Editor on any map and return the "worldName" value in the debug console, it will say e.g. "Altis". Now if you save and load the game and try it again, it will display "altis" instead.
This only happens after you save and load the game and will persist even after restarting the mission from the "Load" menu or from the Eden Editor. It seems to be "fixed" after you switch to a different map in the Eden Editor and then switch back to the other map, but it'll reoccur again after saving and loading.

I'm not using any mods which could cause this behavior.

Here are some examples on Altis and Stratis: