Two things to check:
1: Are the tracks frozen? If so, transposing might not work.
2: Are there WAV or other Audio files (e.g. mp3) in the same folder as the BiaB song with the same name as the BiaB song? If so, BiaB may be playing and you might be listening to the existing audio rather than BiaB output.
YES! The danged tracks were frozen! Completely overlooked that... definitely one of those senior moments!
Next time I have one of these "usually works but..." moments, I'll post in the Beginner's Forum.
Thank you @VideoTrack!
BIAB, RealBand, Bandlab Cakewalk,Kontakt5, Cantabile3, SampleTank4,VB3,
Kurzweil-88key, AXIOM-61key & IKiRigPro-32key boards, Roland SD-50 MIDI, Behringer 404HD audio interface, Win10-64