Please make sure that you are in the correct View when inserting the page breaks. Two ways to check:
- check at the bottom right corner while you are on Design tab. Does it show "Web View" or "Page View"?
- or select the "View" menu in the app menu and check what is selected.
If you want page breaks to show in the pdf form, then you will need to select "Page View" and then add the page breaks. If you want the page breaks to show in the html form then you need to add the page breaks in "Web View".
Please note that in "Page View", if you do not manually add any page breaks, page breaks are automatically added as well based on the paper size/orientation that you specified in File menu - Form Setup - PDF Paper Size / Orientation.