I was quite sure that I have used this before in BIAB and it worked fine but now I am not sure.
When I am testing it now it does not work.
It seems that a chord only plays when there is a chord change.
So a series of the same chord only play once and a series of alternating chords will play on each chord as far as I can see.
Maybe there is a setting somewhere.

(I mostly use EZKeys for this nowadays since I often need the chord structure there as well.
When I am starting from scratch, the "add standard groove" will get eight basic chords in the key for the song in the song line and each chord is playing once for each bar, it is only to change, add or remove as needed.
If I go from SongMaster Pro I export to MusicXML and 1) import it to BIAB it seems to work fine now. 2) import it to Musescore and export it to a midi file which I then drag into EZKeys and then I have it all in both BIAB and EZKeys (and the recently updated EZBass 1.2 now imports EZKeys2 files directly)).