Preview option to "export as PDF" has disappeared, and files are not being saved.

Using Ventura 13.4, and am unsure when it last updated.

However, I've used Preview to "Export as PDF" on numerous occasions, yet that option is greyed out since I began to scan some documents from my printer.

Furthermore, when I just "Save" to a given folder, the file cannot later be found there, or anywhere except in Recents.

I've even created a new and important folder for an audit that I now cannot find.

If I go to Finder and to the folder where I created the subfolder, it is not there; and many of the documents I've recently saved are also not visible.

Yet the next time I save to a folder, the folder (including the missing one) appears. I just can't do anything with it except add to it---

Help please!