My CSGO server recently started a new behaviour: When I use a Workshop collection with more then one map, the server loads de_dust instead, despite what parameter I put in command line "workshop_start_map". Map voting does not work either. Collections with one map loads the right map. Default maps groups like mg_bomb works fine!
I have reloaded all my server files (steamcmd & csgo-ds folders) from scratch using default Valve techniques and the error is reproducible. I am experiencing this behaviour on a 2012 x64 server and have been able to reproduce the error on a Windows 8 Pro x64 machine. I am currently downloading on my Ubuntu to see whether the same behaviour applies to Linux servers.