I see the problem now. The natural A sounds especially out of place on a G7b9 chord. With a G7#9 the bass line seemed to avoid this however.

I flagged up a similar problem with the way bass lines sometimes work in BIAB which wasn't taken up by anyone. It seems that in many of the jazz styles the bass will ignore a b9 and simply play a major triad or 7th chord figure instead.

The issue for me can't be explained away by saying that the bass is keeping out of the way. If you have a 'bass and drums only' accompaniment you want the bass line to reflect the harmony better than this. You might get away with it in a tune with lots of changes, but in any other setting, say a modal tune, it sounds plain wrong.

Regards

Alan