CPFC1985
I'm sure I set it up last time that no MIDI would show in screenset (n) and no audio would show up in screenset (n+1).
The only way I can think of is...
1. Create two track folders in screenset (n) and name them "Audio" and "MIDI."
2. Put all audio tracks into the Audio folder and all MIDI tracks into the MIDI folder.
3. Collapse the MIDI folder and lock the screenset.
4. Duplicate the screenset to screenset (n+1).
5. Unlock the screenset (n+1), expand the MIDI folder and collapse the Audio folder, then re-lock the screenset.
6. When you add an audio track in screenset (n), right-click on one of the existing audio tracks in the Audio folder and select "Insert Audio Track."
7. When you add a MIDI track in screenset (n+1), do the same on one of the existing MIDI tracks.
Maybe this is what you used to do?