I'm unable to use the dropdown to change the currently selected world. Navigating to it by address works.

I guess it has something to do with checking the wrong variable here.
https://github.com/BlueMap-Minecraft/BlueMap/blob/master/BlueMapCore/src/main/webroot/js/libs/bluemap.js#L982

This will be fixed when merging #6

Fixed with fa0d13f