matplotlib widgets fail to load

Describe the issue

Get a line like [<matplotlib.lines.Line2D at 0x7f610447e140>] when trying to plot, and an 'empty' plot which seems to have a toolbar of button, but no content.

developer tools console has:

Failed to fetch ipywidgets through the "jupyter.widget.control" comm channel, fallback to fetching individual model state. Reason: Control comm was closed too early
_loadFromKernel @ manager-base.js:291

Versions

 3.10.8 (main, Nov 30 2022, 11:24:29) [GCC 10.2.1 20210110]
ipympl version: 0.9.2
Selected Jupyter core packages...
IPython          : 8.7.0
ipykernel        : 6.18.3
ipywidgets       : 8.0.2
jupyter_client   : 7.4.7
jupyter_core     : 5.1.0
jupyter_server   : 1.23.3
jupyterlab       : 3.5.1
nbclient         : 0.7.2
nbconvert        : 7.2.5
nbformat         : 5.7.0
notebook         : 6.5.2
qtconsole        : not installed
traitlets        : 5.6.0
Known nbextensions:
  config dir: /home/zlobko/.pyenv/versions/3.10.8/etc/jupyter/nbconfig
    notebook section
      jupyter-matplotlib/extension  enabled
      - Validating: OK
      jupyter-js-widgets/extension  enabled
      - Validating: OK
JupyterLab v3.5.1
/home/zlobko/.pyenv/versions/3.10.8/share/jupyter/labextensions
        jupyterlab_pygments v0.2.2 enabled OK (python, jupyterlab_pygments)
        jupyter-matplotlib v0.11.2 enabled OK
        @jupyter-widgets/jupyterlab-manager v5.0.3 enabled OK (python, jupyterlab_widgets)

Other labextensions (built into JupyterLab)
   app dir: /home/zlobko/.pyenv/versions/3.10.8/share/jupyter/lab

The following source extensions are overshadowed by older prebuilt extensions:
    @jupyter-widgets/jupyterlab-manager

FWIW: This is on debian/WSL2 (which was converted from WSL1).

matplotlib / ipympl

matplotlib widgets fail to load #504

Describe the issue

Versions