Presumably, the existing RH project was created by either importing or linking the FM content to the RH project. When you do that, you select the Paragraph tags that you want to use to divide up/split the FM content into separate topics in the RH project (it's called "pagination" in the Settings screen in RH). No need to do that in FM - just make your changes to the content in FM and import or synch the changes with the RH project. If you go the Import route, create a new, empty RH project to populate with FM content.