Why does monitor button have to be on to hear tracks

I am using my motifxf as an external synthesizer. I have an audio channel and a midi Channel paired up to do this. But I have to have the monitor buttons on in order to hear the motif. I don’t understand why this should be. Even when I Record and play back via the midi track, I still need the monitor buttons active; otherwise, no sound.
In what sense am i monitoring? It seems to me, that I am mixing at this point. If I had 20 channels playing back would I need to switch on all 20 Monitor buttons?
This goes against my intuition, but clearly I am missing some piece of insight.
Oy. Just when I think I’m getting the hang, some new puzzle comes along.
By the way I’m using 10.5 artist.

Wait. I think I know why.
It’s because no audio track has been actually recorded. When the midi track triggers the motif, it’s actually as if a musician was playing it live since new audio is being sent from the motif back to cubase via the interface.
My mental schematic is not quite there. But making progress.

Yup. What you are “monitoring” is the audio signal coming into the Track from somewhere else. The Monitor button says to listen to the audio coming into the Track instead of what is already on the Track.