getInteractiveLegendEvents onLegendClick not called with ChartBar in ChartStack + ChartAxis

[sachaudh]

Description

getInteractiveLegendEvents's onLegendClick callback is never invoked when ChartBar components are wrapped in ChartStack (or ChartGroup) alongside ChartAxis. The same setup with ChartArea instead of ChartBar works correctly.

Steps to reproduce

1. Create a Chart with ChartAxis, ChartBar inside a ChartStack, and a ChartLegend
2. Pass getInteractiveLegendEvents({ chartNames, legendName, onLegendClick }) to Chart's events prop
3. Click a legend item
4. onLegendClick is never called

Minimal reproduction

<Chart
    events={getInteractiveLegendEvents({
        chartNames: [['bar-0'], ['bar-1'], ['bar-2']],
        isHidden,
        legendName: 'legend',
        onLegendClick: handleLegendClick,
    })}
    legendComponent={<ChartLegend name="legend" data={legendData} />}
    containerComponent={<ChartContainer />}
>
    <ChartAxis />
    <ChartAxis dependentAxis />
    <ChartStack>
        <ChartBar name="bar-0" data={data[0]} />
        <ChartBar name="bar-1" data={data[1]} />
        <ChartBar name="bar-2" data={data[2]} />
    </ChartStack>
</Chart>

Full repro: https://github.com/sachaudh/pf-legend-click-repro

What works vs what doesn't

Setup	onLegendClick fires?
ChartArea + ChartStack + ChartAxis	Yes
ChartBar + ChartAxis (no wrapper)	Yes
ChartBar + ChartStack (no ChartAxis)	Yes
ChartBar + ChartStack + ChartAxis	No
ChartBar + ChartGroup + ChartAxis	No

All three ingredients are required to trigger the bug: ChartBar, a ChartStack/ChartGroup wrapper, and ChartAxis.

Workaround

Apply click events directly to ChartLegend's events prop instead of relying on Chart-level event dispatch:

const legendClickEvents = [
    { target: 'data', eventHandlers: { onClick: handleClick } },
    { target: 'labels', eventHandlers: { onClick: handleClick } },
];

<ChartLegend name="legend" data={legendData} events={legendClickEvents} />

Affected version

@patternfly/react-charts v8.4.1, Victory v37.3.6