I did some tests by selecting the same engine (subtractive in this case) on the 3 first Tracks with “Stereo” FX on each track.
And what i found out is when you raise the number of polyphony voices the behaviour is not the same from Track-1 to Track-3.
For Track-1 when i raise the number of polyphony voices it also updates on “Stereo” FX inputs display.
For Track-2 and 3 when raising the number of voices it doesn’t update on the “Stereo” FX inputs display.
Another thing is when for Track-1 i set the engine to “none” (no engine selected) and raise the number of polyphony voices then it doesn’t update the “Stereo” FX inputs display. Though when i do the same for Track-2 a 3 then “Stereo” FX inputs display update correctly.
So to summarise there is sommething strange with the polyphony encoder behaviour from track to track.