Shape Layer example not working for layer='between' and yref='y domain'

Hi! Since latest plotly version 5.21 a great addition has been considered by @my-tien pull #6927 being capable of specifying shape layer as 'between' which should solve issues such as presented in https://github.com/plotly/plotly.js/issues/4106.

Example shown in https://plotly.com/python/shapes/ section Shape Layer works fine as it is, but it is not producing expected results when specifying yref='y domain' for the layer='between' subplot. As a mre, the following code:

import plotly.express as px

df = px.data.stocks(indexed=True)

fig = px.line(df)

fig.add_shape(
    type="rect",
    x0="2018-03-01",
    y0=0,
    x1="2018-08-01",
    y1=3,
    line_width=0,
    layer="above",
    label=dict(text="Above", textposition="top center", font=dict(size=15)),
    fillcolor="LightGreen",
    opacity=0.80,
)

fig.add_shape(
    type="rect",
    x0="2018-10-01",
    y0=0,
    x1="2019-03-01",
    y1=3,
    yref='y domain',  # consider y domain
    line_width=0,
    layer="between",
    label=dict(text="Between", textposition="top center", font=dict(size=15)),
    fillcolor="LightGreen",
    opacity=0.80,
)

fig.add_shape(
    type="rect",
    x0="2019-05-01",
    y0=0,
    x1="2019-10-01",
    y1=3,
    line_width=0,
    layer="below",
    label=dict(text="Below", textposition="top center", font=dict(size=15)),
    fillcolor="LightGreen",
    opacity=0.80,
)

fig.show()

Produces this unexpected figure:

まず、Plotly ドキュメントの Shape Layer セクションにある提供された Python 再現コードを実行し、yref='y domain' と layer='between' の結果を比較します。次に、fig.add_shape がこれらの設定を Plotly.js の shape レンダリングパスにどのように渡しているかを追跡し、その後、between レイヤーの矩形が期待どおりに配置され、レンダリングされることを確認します。