[Python] Subplot spacing with scaleanchor and constrain in plotly

I am trying to create a figure with three subplots. The bottom left subplot is supposed to be a 2D histogram with projections on the top and right sides. The 2D histogram is supposed to be square (hence, the scaleanchor=x3) and I would like to use constrain='domain' to keep the 2D histogram tidy.

With the code shown below, the right projection has a far greater spacing than the top projection (see image). They are supposed to have the same spacings. How can I fix this?

This is my MWE:

import plotly.graph_objs as go
from plotly.subplots import make_subplots

fig = make_subplots(
rows=2, cols=2,
shared_xaxes=True, shared_yaxes=True,
column_widths=[0.8, 0.2],
row_heights=[0.2, 0.8],
horizontal_spacing=0.02, vertical_spacing=0.02,
)

fig.add_trace(go.Bar(), row=1, col=1)
fig.add_trace(go.Bar(), row=2, col=2)
fig.add_trace(go.Heatmap(), row=2, col=1)

fig.update_layout(
xaxis3=dict(range=[0, 1], constrain='domain'),
yaxis3=dict(range=[0, 1], constrain='domain', scaleanchor='x3'),
)

fig.show()


Example output using randomly generated data:



Continue reading...