Is this a question? In any case, barlines between staves are normally not used, because of this very problems.

Dorico has a quite satisfactory set of vocal options that avoid bar lines between vocal staves.

It's possible that Dorico might not identify staves from an XML import as being "vocal" -- if you've renamed them to "Douglas" and "Cynthia" perhaps. If it doesn't know, it will assume that they are a Flute. (You'll be able to tell by the playback.)

In which case, you'll need to change the instrument in Setup mode to a vocal staff. Once that's done, Dorico treats vocal staves differently from instruments, putting the dynamics above and not having barlines inbetween. 

If you have any question about Dorico, it's best to head over to the Dorico forum, which is generally quite helpful.