Are you attempting to view the autobackups from within your MS Windows File Explorer in the folder where you expect your project to be, or are you trying to view them within yWriter itself and not finding them?
If you are doing the latter, only Simon can help. But if you are doing the former, can I suggest you go into yWriter to see if the autobackups for your project are displaying in yWriter - you can do this under Tools>Backups>View Autobackups. You will see a list of dates that represent all dates the project was opened which, if you click on, some will have scene backups sorted by time saved, but some might have nothing if you only opened the project but did not change anything, so try all the dates to see if there's backed-up scenes in them. If you can see backed-up scenes, your project is saved in a location different to where you think it is but you have not lost anything, you just need to identify where it is saved now.