Weird vertical lines for ff.create_annotated_heatmap

Dash Python
1

Hi,

I have a weird issue with the ff.create_annotated_heatmap function:
image
For all the nan value, it has a vertical line, which is disturbing

    import plotly.figure_factory as ff
    layout = go.Layout(title = title, 
            xaxis = {'title': 'FUNDCD'}, 
            yaxis = {'title': ytitle},
            plot_bgcolor='white',
            height = 100 + len(heatmap_df) * 50)

    fig = ff.create_annotated_heatmap(
                   z=heatmap_df.values.tolist(),
                   x=list(heatmap_df.columns),
                   y=list(heatmap_df.index),
        )
    fig.layout.update(layout)

I wonder if there’s a way to remove those lines.