Box plot with gaps in categores

[Zygonyx]

I am trying to generate a box plot using subsets of a larger data set. When I show the plot, there are strange gaps in the data. is there a way to center each plot over the correct label. Also, can I remove the redundant labels in the legend?

fig = go.Figure()
melted_data = melted_data.sort_values(['model', 'alpha'])
for model, alpha in zip(combos['model'].to_list(), combos['alpha'].to_list()):
    data = melted_data[(melted_data.model == model) & (melted_data.alpha == alpha)]
    fig.add_trace(go.Box(
            y= data['value'],
            x = data['model'],
            marker_color=colors[alpha],
            name = alpha,
            boxmean=True,
            alignmentgroup = 0
        ))
#     print(i)
#     i = i +1
fig.update_layout(
    showlegend=True,
    boxmode='group', # group together boxes of the different traces for each value of x
    boxgap = .1)
fig.show()