StackedBarSeries tooltip doesn't show negative value instead it shows label

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped wo

Google's docs say to add isHtml: true under tooltip: https://developers.google.com/chart/interactive/docs/customizing_tooltip_content#using-html-tooltips

but that doesn't seem to work with this library

Repro: https://hjwtp.csb.app/

<Chart
  options={{
    backgroundColor: "#222",
    tooltip: {
      isHtml: true
    }
  }}
  chartType="GeoChart"
  data={[
    [
      { t

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report