I just tested version 19.07.15 on Windows, and it is working for both saved and unsaved (Untitled) projects. Autosave only occurs every 30 seconds if the current project is considered modified (on Windows an asterisk appears in the title after the project/mlt-file name). If you were working on a named/saved project, then Shotcut does not offer to recover until you attempt to reopen that project.
