Nice quick save function...that doesn't work...
Hmm, it does work though. For me and everyone else I asked. No one else has reported this as a bug.
The Quick Save files are located in the "Q" tab on the Load and Save menus. At the bottom, there is A Q 1 2 3 4 5 ... etc. Hit the Q.
A message pops up when you hit the Quick Save button. --> "Quick save complete."
Are you on Windows, Mac, Linux or Android? I've tested it on both Windows and Android just now, works perfectly.