By default, notes in slash voices are not played back. You can include/exclude all notes in slash voices project-wide in playback.
Procedure
- Press Ctrl/Cmd-Shift-P to open Playback Options.
- In the category list, click Repeats.
- In the Rhythm Slashes section, activate/deactivate Play slash voices.
- Click Apply, then Close.
Result
All notes in slash voices project-wide are included in playback when Play slash voices is activated, and excluded when it is deactivated. When slash voices are included in playback, notes in slash voices play back with their input pitch.