Missing end-of-stave barline?

[Mark Probert]

Hi.

When I run this snippet the barline at the end of first stave, which
I think should be a “||”, goes “missing” (there is no barline at all).

Is there a correct way of setting the end of stave barline in this kind of
situation?

%% ——
\version "2.24"

parta = {
  aes4 bes c d | d4 ees f g |
}

partb = {
  aes,2 c2 | ees1 |
}

tune = \relative c'' {
  \clef treble
  \key c \minor
  \time 4/4

  \parta \bar "||" \break
  \repeat volta 2 {
     \bar "[|:" \partb \bar ":|]"
   }
}

\score {
  \new Staff      \tune
}
%%—

TIA,
  -mark.