Footnote formatting>"Apply changes to selected text" not limiting changes to selected text

[Swarup]

In a particular section, if I highlight one footnote call number, then go to the footnote formatting window and in the footnote numbering field select my chosen number format, and in the field "Apply changes to", opt for "Apply changes to selected text", it is not limiting changes to selected text. There are three options: Apply changes to (1) selected text, (2) selected section, (3) whole document. But even if I opt for "selected text", it is changing the footnote call number format for all the call numbers in the section, rather than limiting it to the call number which I have highlighted. How can I get this "selected text" option to work?