Originally Posted by AudioTrack
Try temporarily changing that track to a MIDI style and see if there is a difference.
Alternatively, try changing that track to some other style (not vibes) and see if there is a difference in what plays on those specific bars / beats. That might assist you to understand that if there are no notes recorded at those positions by the recording artist, then there is nothing available to play back.

Thanks.
The further and further I go down this rabbit hole the more complicated and weird things get.
One thing about BIAB that's a certainty.
There's never a dull moment with the program. frown

I couldn't figure out how to swap the audio parts for midi so I went for a change of style.
I swapped _SMALLHR for _SJAZZC1 and got more unexpected results.

I am working with the same chords:
Bar 5 has a 'main chord' of C plus two micro chords, (C,G) and (C,G) on beats one and two.
Bar 9 has NO 'main chord' but has two micro chords, (C,G) and (C,G) on beats one and two.

This is what I heard:
Bar 5 played the micro chords straight this time using the Electric piano and bass played them too.
Bar 9 played the micro chords straight this time using the Electric piano and bass played them too.
BUT along with this a C chord was played right after the micro chords DESPITE there being NO C CHORD
in the chart!
It did it in bar 5 and 9.
So once again unexpected results.

Not to mention the highly disturbing liberties that BIAB is taking, by ignoring the chords I typed in!
Playing a bunch of upper extensions on my F7 chord and changing one of my G chords to G7! frown

A BIAB user for more than 30 years (if you can believe it) !