I have also tried correcting the notes manually.... for example in the style 'back street top 40' I wrote Em/B again but the bass was playing an E on the strong beat, so basically the chord sounded like a straight Em. But I moved the bass note from E to B and it stays there if I control the playback of the song by just clicking in the chord sheet window. If I click the play button, the bass reverts to the E note.

I'll try to modify the harmony in that way.....hopefully it will work