Can't add ScatterPlot on top of Treemap

I’m trying to display a ScatterPlot on top of a Treemap, but I can’t see the ScatterPlot when I do this:

fig = go.Figure()
fig.add_scatter(x=X1[:,0], y=X1[:,1], mode='markers')
fig.add_trace(go.Treemap(labels = ["Eve","Cain", "Seth", "Enos", "Noam", "Abel", "Awan", "Enoch", "Azura"],
    parents = ["", "Eve", "Eve", "Seth", "Seth", "Eve", "Eve", "Awan", "Eve"],
    root_color="lightgrey"))
fig.add_shape(type='rect', x0=0, y0=0, x1=50, y1=50, line=dict(color='Black', width=5))

app.layout = html.Div([
    dcc.Graph(id='graph', figure=fig),
...

Adding the shape on top of it does work, and in the user interface, I can see the tool that selects points.