I'm a little late to the topic since the problem has been solved as described. But, perhaps it has something to do with the 2 places that need to be selected for shots, holds to be activated in the song file as it is saved. So far this solution has only been applied to RealTracks not a MIDI only style but why not try both settings anyhow to see what happens.
Review this thread for potential solution.
http://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Main=51203&Number=352259#Post352259

There are 2 settings to check in order to get Shots, Holds and Pushes to behave with RealTracks in BIAB 2016. (and perhaps other versions)

A: Preferences | RealTracks | RealTracks Settings dialog ' [_] Allow RealTracks Shots, Holds and Pushes

B: Song Settings (above the tempo box) |
[_] Allow RealTracks Shots, Holds and Pushes.

I could not get my chords to hold (sustain) until I had found and checked both of these.


Does the noise in your head bother me ?