I had this with especially RT basses, especially on chord changes at 2nd, 3rd, and 4rd beats at a chord change. Not swing style specific though, but with other styles too.

Some times you can fix this by pointing to the right bass note by specifying the bass, like entering Gmaj7/B if you need a B note for bass at a certain beat. Sometimes i split a 4/4 bar up in two 2/4 bars, or even mark the bar start with a substyle marker (blue for a or green for b) to force the chord to the root note at a certain beat.

Quite often with realtracks this 2/4 bar split trick however causes empty beats in the realtrack, or worse, doesn't select the right chord on a certain instrument, as f.i. a Gmin is selected sounds when you want a G. I report the latter type of errors with PG as they probably are programming faults. F