Hello David,
Thank you for reaching out.
Please note that in order to restore a project from an autosave, you need to move the autosave to the original SBS file location, then rename it to the original file's name (see attached GIF). The original file can be deleted, or renamed to '<name>_original.sbs' for instance.
As a first step, please confirm you follow these steps when restoring from an autosave.
For your information, you can choose the auto-save time period, as well as the maximum number of files to be kept at all times, in the 'Edit > Preferences > General' menu (see attached GIF).
If these steps do not solve your problem, we will investigate further and ask you more details about your system and usage of Substance Designer.
Best regards,
Luca Giarrizzo
[Attachments]
DEMO_AutoSave-1.gif
DEMO_AutoSave-2.gif