Problem in Multi-category axis BarPlot with stacked barmode and unified hovermode

Hello community,
i want the “x unified” hovermode for some multi-category xaxis, but I only get the last trace hoverd (picture below).
Is there a chance to get the “x unified” hovermode for all stacked elements, like in plots with one category xaxis?

Thanks a lot!

fig = go.Figure()
fig.add_trace(go.Bar(
    x=[['First', 'First', 'Second', 'Second'],
       ["A", "B", "A", "B"]],
    y=[2, 3, 1, 5],
    name="Adults"))
fig.add_trace(go.Bar(
    x=[['First', 'First', 'Second', 'Second'],
       ["A", "B", "A", "B"]],
    y=[8, 3, 6, 5],
    name="Children"))
fig.update_layout(title_text="Multi-category axis",
                  barmode="stack",
                  hovermode="x unified")
fig.show()