Is this Word for Windows? In the main body of the document, click in a Heading 1 paragraph. Click Home > Multilevel List > Define New Multilevel List. Verify that the settings are correct for all numbering levels. In particular, you want to make sure that restarts are correctly set for all levels. Sometimes, you have to delete and recreate numbering formats that have become wrong. Just add the numbering for each level, include any higher level numbers, and type in the periods. See also https://shaunakelly.com/word/numbering/numbering20072010.html. The corresponding resources that apply to Word for Mac can be found at https://www.brandwares.com/bestpractices/2016/06/outline-numbering-in-word-for-os-x/.
