Where do my AutoSaves go?

Do I not have AutoSave on? Under ‘Advanced’ in ‘Preferences’, I have Auto Save set for every 20 minutes.

It doesn’t seem to be working? Is there something else I have to turn on?

Also, where do my backups cache? I’ve tried saving my latest version of a file, only to get a prompt “X Failed to Save”. Then, I go looking, and there have been no Saves over the previous 20 minute intervals. Are there backups somewhere where I can find them?