Notes->Transpose gets octave wrong for some notes with transposing instruments

Windows 7, GIT commit: 5363f93

1) new score for Bb clarinet (key of C, 4/4)
2) verify concert pitch is off (the default)
3) enter a D major scale: "N D E F G A B C D"
4) exit note input mode
5) select all
6) notes / transpose
7) by interval / down ./ major third

Result: the Bb's are in the wrong octave

This seems to be true for any transposition that would result in a B or Bb

Seems related to #25275: [2.0] Bb Clarinet Bb and B notes transposed, but that one is still fixed.