Can't draw spike line across subplots with make_subplots in 4.0.0

After upgrading to plotly 4.0.0, I can't see how to create a spike line across shared axes created with make_subplots.

Previously I was using code like this:

from plotly.tools import make_subplots
from plotly.io import write_html

fig = make_subplots(rows=4, cols=1, shared_xaxes=True)
x_vals = list(range(10))
y_vals = [x**2 for x in x_vals]
fig.add_scatter(x=x_vals, y=y_vals, row=1, col=1)
fig.add_scatter(x=x_vals, y=y_vals, row=2, col=1)
fig.add_scatter(x=x_vals, y=y_vals, row=3, col=1)
fig.add_scatter(x=x_vals, y=y_vals, row=4, col=1)

fig.update_xaxes(spikemode='across+marker')

write_html(fig, 'out.html', auto_open=True)

The resulting figure showed spike lines across axes because only one x axis was created:

But in 4.0, multiple x axes are created so the spike line no longer draws across all subplots:

Is there any way around this? Thanks!

从提供的 Python 复现开始，使用 make_subplots、shared_xaxes 和 fig.update_xaxes(spikemode='across+marker')。将 Plotly 4.0 中生成的子图轴配置与之前的单轴行为进行比较。完成标准是确定一种受支持的方式，使 spike 线跨越所有共享子图，或记录该限制及其变通方案。