A family of Microsoft word processing software products for creating web, email, and print documents.
Stefan and Bob have given you good answers.
There is a huge difference between a Next Page Section Break and a Manual Page Break. The Section Break starts a new section. If you restart numbering in any section and then start a new section from within that, the new section will by default restart page numbering. You can reset that at any time with the Format Page Numbers dialog.
Like Bob, I seldom use Manual page breaks. Formatting the paragraph to start the new page with Page Break Before formatting is preferable and is easy to do if I use a heading style to start the new section and simply have that style set for that. I never use section breaks just to start a new page, which is what you must have done. There are great reasons to use section breaks, but that is not one of them. Manual page breaks can be applied easily. In the Windows version it is Ctrl+Enter; I think in the Mac version it is likely Cmd+Enter. However in important documents, you will end up with messed up formatting if there is much revision done. The Page Break before paragraph formatting avoids that problem.
For more background, take a look at:
- What gets carried over when you start a new Section?
- Quick Reference Card for Page Numbers, Headers, and Footers https://www.addbalance.com/word/download.htm#hfQuickReference
- When to use, and not use, Section breaks.