Drum Maps>I-Notes, O-Notes, and Pitches
A drum map is a kind of filter that transforms notes according to the settings in the map. It does this transformation twice; once when it receives an incoming note, that is when you play a note on your MIDI controller, and once when a note is sent from the program to the MIDI sound device.
MIDI Input → Drum Map: I-Notes to Notes(Pitch) transformation → Expresson Map: Remote
→ Expression Map: Output → Drum Map: Notes(Pitch) to O-Notes transformation → Instrument
Maybe because of this.