MIDI PC will not pass to iOS on channels with VST/AU generator instantiated

Using Studiomux in Ableton Live 10 with MIDI clips to activate program changes via MIDI:

-MIDI PC will NOT pass to iOS when on sent as the same channel where the VST/AU generator is instantiated.

  • MIDI PC will pass to iOS on channels when the audio device created by Studiomux is used instead of the VST.

Why???