Strange sound

With accordion scores. After writing the name of a chord, at least in Spanish, mainly with 'Do...', either M,m, or 7, also with Fa, when I leave the Text Mode, or if I click later on the name of the chord, it sounds a piano note an this sound is heard when playing the song.
Please listen carefully at the measures where the names of the chords Do or Fa are writen.
See attached file with a sample score. ESTUDIANTINA PORTUGUESA.mscz