Can't save Numbers document to PDF

MacBook Air M1 2020, Ventura 13.4.1

I select Export to PDF from the File menu, a message tells me "document can't be autosaved, and then I click Export Your Spreadsheet window opens, and I select PDF and Save

Window with Save As and Where opens, and I select Export

Window "The document could not be autosaved, and I click OK (the only choice), and I'm back to the beginning.

I've also tried "Save as PDF" from the Print mode, but that doesn't work either.

Can anyone help?