I'm in the same boat as you. The BIAB plugin will not sync in Cakewalk by Bandlab, at least not for me. I can add the plugin, I can import a song, but,
1. the drag-and-drop feature to set the tempo and show the chord progression in a midi channel does not work, and - more importantly -
2. Cakewalk will not play the BIAB chords. I'll get a "blurp" of the tracks and then nothing. It plays for the same length of time as the sound of the space bar being pressed.

The plugin USED to work with Cakewalk, but it definitely does not anymorre.