It's quite possible that there is a problem with the servers that are running on Linux.
I personally run a private cluster on Linux and I noticed that the the steam install directory changed from .steam/SteamApps/..... to .steam/steamapps/.....
This would not be a problem on windows, since windows does not care about capitalization. This is however not the case for Linux.
One has to adjust the startup scripts in order to fix the issue.