Running a cell producing a plot for a second time, and the plot fails to display

[stevejpurves]

Describe the issue

When using ipympl with the %matplotlib widget magic, I can successfully display a plot. Rerunning the cell with the plot however, fails to re-display the figure.

the following is visible in the error console

Note: that adding plt.show() to the cell and re-running does display a plot however the color of the line in the plot is different, suggesting that this is a new (second) matplotlib figure and not the original.

Versions

 3.8.10 | packaged by conda-forge | (default, May 10 2021, 22:58:09) 
[Clang 11.1.0 ]
ipympl version: 0.9.3
Selected Jupyter core packages...
IPython          : 8.10.0
ipykernel        : 6.21.2
ipywidgets       : 8.0.4
jupyter_client   : 8.0.3
jupyter_core     : 5.2.0
jupyter_server   : 2.3.0
jupyterlab       : 3.5.3
nbclient         : 0.7.2
nbconvert        : 7.2.9
nbformat         : 5.7.3
notebook         : 6.5.2
qtconsole        : not installed
traitlets        : 5.9.0
Known nbextensions:
  config dir: /Users/stevejpurves/.jupyter/nbconfig
    notebook section
      jupyter-js-widgets/extension  enabled 
      - Validating: OK
  config dir: /Users/stevejpurves/miniconda3/envs/em_recharge/etc/jupyter/nbconfig
    notebook section
      bqplot/extension  enabled 
      - Validating: OK
      ipyevents/extension  enabled 
      - Validating: OK
      ipysheet/extension  enabled 
      - Validating: OK
      ipytree/extension  enabled 
      - Validating: OK
      jupyter-leaflet/extension  enabled 
      - Validating: OK
      jupyter-matplotlib/extension  enabled 
      - Validating: OK
      jupyter-js-widgets/extension  enabled 
      - Validating: OK
JupyterLab v3.5.3
/Users/stevejpurves/miniconda3/envs/em_recharge/share/jupyter/labextensions
        ipytree v0.2.2 enabled OK
        jupyterlab_pygments v0.2.2 enabled OK (python, jupyterlab_pygments)
        bqplot v0.5.37 enabled OK (python, bqplot)
        jupyter-matplotlib v0.11.3 enabled OK
        jupyter-leaflet v0.17.2 enabled OK
        ipysheet v0.7.0 enabled OK (python, ipysheet)
        ipyevents v2.0.1 enabled OK
        @jupyter-widgets/jupyterlab-manager v5.0.5 enabled OK (python, jupyterlab_widgets)

[stevejpurves]

I am assuming this is unexpected behaviour, as I don't recognize it from previous version, but am unsure.

[juhaszp95]

Just leaving a comment here to say that I see the same behaviour with an up-to-date ipympl (0.9.7) now.