The chords are /Db7 C7/ and there are vibes, bass and drums.

One would expect the bass to play a Db on the Db7 chord and then a C on the C7 chord.
The chords are on beats one and three.
But BIAB doesn't do this. It just plays C for the whole bar!


They will play properly in a new song with none of my song chords entered.
Just a couple of bars in the new song, the second being /Db7 C7/ .
That works, but it doesn't work in my song.

A BIAB user for more than 30 years (if you can believe it) !