chorus staff then hymn

[Brother Gabriel-Marie]

My hymn starts with a chorus and then goes to the verses, so I want to put the chorus on its own staff, then put the verses together as numbered lyrics.

Problem is that the staves always group together as if they were polyphony and I don't want them grouped.
I tried without \staffgroup but it doesn't work.

How can I make it stop and start over?

\score {
        \new staffgroup   <<
           
            \new staff {
                \chorusMelody
                \addlyrics { \chorusLyrics }
            }
        \new staff {
                \melody
                \addlyrics { \wordsOne }
                \addlyrics { \wordsTwo }
                \addlyrics { \wordsThree }
                \addlyrics { \wordsFour }
                \addlyrics { \wordsFive }
                \addlyrics { \wordsSix }
            }
    >>

}