i.e you play the notes but can only hear them later when they are sequenced back - the sequenced midi instrument is not played via external auto channel input, so you are playing ‘blind’ so to speak - although you can get clues from an internal voice perhaps, but for normal MIDI use this is lacking
The Auto Channel also needs to pass MIDI out, just as the onboard pads/keys do so that the new MIDI functionality can be played along with recorded via all available input methods