Bill:

I assume you're using BIAB for windows, 2021, and the latest update.
Check a couple of "gotchas":
- check the mixer to make sure the volume is turned up on the Melody track
- open the Piano Roll window for the Melody track and check the Velocity values at the bottom of the window

Otherwise, if you want to post the BIAB file here, someone can likely help.
Good luck!
LLOYD S