The first plot is not showing in vscode interactive window, using the "notebook_connected" renderer.
I'm using the following code (note the # %% is used to enable vscode interactive window):

# %%
import plotly.express as px
import plotly.io as pio

pio.renderers.default = "notebook_connected"
px.line(x=list(range(10)), y=list(range(10, 20))).show()

# %%
px.line(x=list(range(10)), y=list(range(10, 20))).show()

# %%
px.line(x=list(range(10)), y=list(range(10, 20))).show()

And the result:

I toggled the dev tool and found a suspicious network error as the following, note the failed request does not have the ".js" suffix.

Additionally, I tried exporting it to HTML (I'm testing the problem in #5068 ), and the HTML works fine, all plots are showing.