https://bugs.winehq.org/show_bug.cgi?id=50586
--- Comment #29 from Arnaud Dovi mr.dovi@gmail.com --- Created attachment 69322 --> https://bugs.winehq.org/attachment.cgi?id=69322 steam-GetVolumePathName.log
GetVolumePathName is not called here. Attaching the log file steam-16615000947893993472-GetVolumePathName.log
I did WINEDEBUG="+loaddll,+volume" so you can see at one point it starts using the X: path.
Could attach another log with +relay if can help you are welcome