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:

  1. Click the Selection Tool.
  2. From the Edit menu, click Select All.
  3. Then from the Edit menu again, click Clear Selected Items.
  4. In the Clear Selected Items window, click the None button.
  5. 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.
  6. Click OK.

If at this point you are still having issues, please submit a support ticket here.