Inserting fields

In LibreOffice Writer, click Insert > Field > More Fields, choose “File name”

All I see in the place of insertion is the word “File name” in a gray box.
Also when inserting Date it shows “Date (fixed)” and when inserting Page number, it shows “Page number”

I thought at one time the actual file name was displayed, as well as the actual date and actual page number. Did something change in an update?

LO (x64) on Windows 10

Click in the menu View>Field names (it’s a toggle).