Can't Access Section/Numbering Settings

I need to make a change to the running head of a chapter of a book I'm formatting, but when I highlight one or even all of the pages in that section and right-click for the Numbering & Section Options panel, the section information is missing. Other chapters show the correct information. Is this a bug, or am I missing something? Just want to know before recreating that section. Thanks in advance for any help.