Default file name for Export Directly as PDF is now blank.

Hi.
For a while now I have noticed when I Export Directly as PDF from writer (7.1.5.2) the Name field for the file in the file dialogue is blank when once it defaulted to the odt file name but with a pdf extension.

I have just been updating some older documents and with these, as long as I have not saved them, Export Directly as PDF has the Name field pre-filled with the file name. As soon as I save the odt file the Name field is no longer pre-filled.

I thought may be this was some setting in LO options but it seems document specific.

Should the Name field in file dialogue to Export Directly as PDF be prefilled with the file name or is this discontinued, if it should be how do I get this to happen.

TIA steve

I think I have this worked out.
If the PDF exists already the Name field is blank.
If the PDF doesn't exist the Name field is filled with the name of the file.

The older files that were working before saving (as .odt) were .sxw.
It would save time hunting down the PDF file to overwrite and avoid a mistake of overwriting a wrong file if the Name field was filled by default.

Steve