My folders are like this:
C:\Spiele\springcontent games & maps
C:\Spiele\spring-91.0 portable engine

Springlobby 0.147:

before clicking "Werkzeuge - Reload maps / games":


after clicking:


the result:


So reloading maplists changes folder of spring.exe to SpringDataDir.
That menu is also a bit bugged:
-To un-grey the textfields I have to check, then uncheck the "Nur im aktuel. Installationspfad suchen" checkbox.

-It takes multiple tries to set the path:
Even if if the textfields show the correct path and "übernehmen" is clicked, SL will pop up the message from the 3rd image.
After that, the path gets set to the SpringDataDir again.
Randomly it will work after a while. Or not, like right now.

hm, now it will not save path to spring.exe at all, it always resets to springdata path...

In case that was not clear:
I set the paths (it even finds them themself with the autodetection function) but they are not saved.
Even when pressing save. ("übernehmen")

Not saved not only as in "they are gone after lobby restart" but they are already gone after going to Singleplayer tab and trying to start a game.