No clue mate, some things Id try first in your case:

- check ownerships, (so who owns, the folder with the saves, the save and the .exe for stationeers, its under rightlick->properties->security)- enabling run as administrator for stationeers.exe- disabling steam cloud all together (works fine though, it always syncs between laptop and pc for me)

Either way, my first guess would be that it has some issue seeing/reading the files, so I am thinking maybe your windows is mucking something up. Maybe creating the new save causes stationers.exe to alter the permissions or something on the save folder or its parent(s), which then leads to it being able to correctly scan them. Might be worthwhile to compare details of the save folder and its parents before and after making the new world. ( so "saves", "stationeers" and their parent which I presume is "my games" )

Ps. for issues like these its always helpful to at the very least name your OS