Blank figures in Jupyter notebook

I have happily used interactive plots in jupyter notebooks for years with %matplotlib notebook. Unfortunately, since version 7 was introduced, I have experienced troubles with getting interactive plotting to work properly. I read that version 7 requires installing ipympl and %matplotlib ipympl.

Today, I set up a fresh virtual environment and installed jupyter and ipympl. Figures are opening, the controls appear, a figure title appears, but the figure contains no content. There is also no error message on the browser's developer console.

Steps to reproduce:

# Create virtual environment
python3 -m venv debug
source debug/bin/activate

# Install jupyter and ipympl
pip install jupyter ipympl matplotlib numpy

# Open notebook
jupyter notebook

Then I use the code from the basic example

%matplotlib ipympl
import matplotlib.pyplot as plt
import numpy as np

fig, ax = plt.subplots()
x = np.linspace(0, 2*np.pi, 100)
y = np.sin(3*x)
ax.plot(x, y)

A white area is opening, the controls appear, but there is no figure content.

I have seen several similar issues on Stackoverflow, where the solution is usually to upgrade or downgrade one of the packages. However, these answers have aged as newer versions came out in the meantime. Is there a general recipe to identify the issue when interactive plotting fails?

Versions

Python: 3.12.3
ipympl version: 0.9.4
IPython          : 8.25.0
ipykernel        : 6.29.4
ipywidgets       : 8.1.3
jupyter_client   : 8.6.2
jupyter_core     : 5.7.2
jupyter_server   : 2.14.1
jupyterlab       : 4.2.1
nbclient         : 0.10.0
nbconvert        : 7.16.4
nbformat         : 5.10.4
notebook         : 7.2.0
qtconsole        : 5.5.2
traitlets        : 5.14.3

jupyter labextension list 
JupyterLab v4.2.1
/home/bene/local/venvs/debug/share/jupyter/labextensions
        jupyterlab_pygments v0.3.0 enabled OK (python, jupyterlab_pygments)
        jupyter-matplotlib v0.11.4 enabled OK
        @jupyter-widgets/jupyterlab-manager v5.0.11 enabled OK (python, jupyterlab_widgets)
        @jupyter-notebook/lab-extension v7.2.0 enabled OK

Riproduci la figura vuota utilizzando i comandi dell’ambiente virtuale elencati e l’esempio di base di ipympl. Inizia controllando le versioni indicate di Python, JupyterLab, notebook, ipympl e widget e la loro compatibilità. Il lavoro è completato quando viene identificata la causa e viene documentata una diagnostica affidabile o una correzione delle versioni dei pacchetti per le figure interattive.