MIDI Track input

Hi! I was eondering about the multiple sources of MIDI inputs in a particular MIDI track.
I’ve discovered that the track input from the “input routing” is not the same as the instrument receives when it is playing back a midi sequence.
Where is that MIDI sequenced signal coming from?
It is revealed when you use Symphonic Choirs and put Wordbuilder as a MIDI insert. Nothing coming from “Input routing” is reaching the instrument, but the notes a re stored in the MIDI track as normal.
When you play back the sequenced notes, the instrument does receive the signal and plays OK even with wordbuilding action. If you switch off the Wordbuilder insert the notes are payed back as regular chords, so the Wordbuilder is absolutely active as a MIDI filter between the sequenced MIDI signal and the instrument that receives that signal.
And… whit Wordbuilder MIDI insert turned off you can play the chords, so the connection among Input routing and the instrument is restored (f course in that case there is not wordbuilding action, but just regular chords)
And… if you turn on the MIDI insert again, and playback the sequenced MIDI notes and you listen the correct choir, and if you try to play over it you won’t get any signal that reaches the instrument… BUT still the Wordbuilder IS receiving your signal because the syllabes step forward with you keystrokes.

So, how is the map there?
Ma be something like this?: