What you describe suggests that numbering hasn't been properly set up.

Click in the first Heading 1 paragraph of your document and then click Home tab | Multilevel List | Define New Multilevel List. In the dialog box, define the numbering for each level and verify that the appropriate heading styles is assigned to the level. Use the "Number style for this level" box to add the number format. Add previous level(s) via "Include level number from." Type in any static text, such as "Unit."

For more, see http://www.shaunakelly.com/word/numb...g20072010.html.

When you are done, you may have to (re-)apply heading styles to text.

__________________
Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional