No Section Break

If you want double bars, add them, from the barlines palette. A section break doesn't do that for you

And they are very different concepts. Section breaks would normlly be used only between movements of a large work, or between songs in a songbook, etc. Really to delineate separate pieces of music that are combined into a larger work. Most pieces will never use them. Double bars, on the other hand, are extremely common. So unless you specifically want the other stuff associated with a section break (including having a pasuse in the playback at that part), don't use the section break at all - use *just* the double bars.