Lyrics extender problem

[Georg Dummer]

Hi all,

I have the following problem with Lyrics extenders. In the "altos" voice it
is drawn properly.
But in the "sopranos" the externder is missed out.

Thanks for any suggestion.
Georg

\version "2.8.0"

global = {
  \key c \major
  \time 4/4
}
    
sopMusic = \relative c'' {
  c4 c c8( b) c4
}
sopWords = \lyricmode {
  hi hi hi __ hi
}
altoMusic = \relative c' {
  e4 f d8( d) e4
}
altoWords =\lyricmode {
  ha ha ha __ ha
}
     
\score {
  \new ChoirStaff <<
    \new Lyrics = sopranos { s1 }
    \new Staff = women <<
      \new Voice =
      "sopranos" { \voiceOne << \global \sopMusic >> }
      \new Voice =
      "altos" { \voiceTwo << \global \altoMusic >> }
    >>
    \new Lyrics = "altos" { s1 }
    
    \context Lyrics = sopranos \lyricsto sopranos \sopWords
    \context Lyrics = altos \lyricsto altos \altoWords
  >>
}