This is most likely caused by embedded MIDI data. Clearing out the MIDI data will let the expression playback definitions and/or Human Playback's interpretation of the score function correctly.
To clear out all your embedded MIDI data, follow these steps:
- Click the Selection Tool.
- From the Edit menu, click Select All.
- Then from the Edit menu again, click Clear Selected Items.
- In the Clear Selected Items window, click the None button.
- With all items unchecked, select the MIDI Data option. It's three sub-sections (Continuous Data, Performance Data, and Tempo Changes) should be checked as well.
- Click OK.
If at this point you are still having issues, please submit a support ticket here.