Preview does not properly save PDFs

When I "export as PDF" a document from Preview in order to file it, I will get the decorative elements but not the text; or sometimes a few dividers and a barcode but again, no text.

The only way I can save something (a PDF) as a PDF is to go to Print and instead "Save to PDF" which I don't always remember to do.

This happened suddenly on my previous Mac, and then when I transferred to a new Mac Air it started happening again.

I don't think I changed any settings.

Thanks for any suggestions.