Build 827 didn't completely fix Bar Settings. 'Change by' doesn't work at all.
Is this for MIDI tracks or RealTracks?
We recently learned that Change-By for RealTracks is significantly different in the degree/severity it applies compared to MIDI.
I'm not suggesting that I agree that it works satisfactorily, but try this:
1:Create a short song with RealTracks (e.g. 4 bars and 10 choruses).
2: Use Bar Settings at bar two and change-by using a value of -100 (yes, that should be a dramatic change in volume).
3: Play the song and listen to determine if the volume actually does noticeably change, but only as several choruses are played.
4: Interested to know what your findings are.