I have a simple example with a ScatterChart (but I think it can be reproduced on any XYChart).
Calling setAlternativeRowFillVisible(true) on this chart does not result in alternative rowfills (as it did in JavaFX 2.x).
I checked the code in XYChart.java and in layoutChartChildren, the isAlternativeRowFillVisible is indeed true, and a Path instance is created for the alternative rows. However, the fill value of this Path is null, and nothing is shown.