Closest alligator to the canoe is the Table of Contents:

Changes to the heading styles associated with the table of contents were as follows:

I linked the default heading styles to each other (Heading 1 style refers to nothing, Heading 2 style is based on Heading 1, etc.). I believe I also changed what heading style follows a given heading for a few of them (Heading 2 follows Heading 1, Heading 3 follows Heading 2, Heading 3 follows Heading 3, and so on for Headings 4 through 9). I also changed spacing (double spaced).

Stefan, thanks for your help.

UPDATE: I just noticed that when I reveal formatting that there appears to be some kind of REF code following all the headings that are appearing in the TOC, but not behind the ones that are falling out. How do I attach those REF codes to the orphan headings?