MIDI has two ways to silence a note:
1: By inserting a corresponding Note off event
2: By setting the corresponding note volume to zero

I understand that BiAB uses the 2nd method.

So if you searched through the MIDI data, you will probably find a note on event but not the other.

You may be able to resolve by editing the MIDI and performing the insertion at the correct location.

BIAB & RB2025 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones