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.