Some mouse wheels are producing event with delta Y = 0.0 right before the actual scroll event which due to the line below causes the map to zoom out on this event. This means you cannot zoom in on the map because it also zooms out right before the zoom in. It also zooms out twice on zoom out.
Some mouse wheels are producing event with delta Y = 0.0 right before the actual scroll event which due to the line below causes the map to zoom out on this event. This means you cannot zoom in on the map because it also zooms out right before the zoom in. It also zooms out twice on zoom out.
https://github.com/gluonhq/maps/blob/60db8e95609cb7002a710ec06282cdac3cf12db5/maps/src/main/java/com/gluonhq/maps/MapView.java#L112
A workaround is to filter out those event in subclass of MapView: