Unable to import numpy and other packages after Ubuntu upgrade

Hi,

I upgraded to Ubuntu 24.04 yesterday. After the upgrade, when trying to import numpy (for example) in JupyterLab, I get the following message:
ModuleNotFoundError: No module named 'numpy'

When I run python from terminal or when I try importing the same package on Jupyter notebook, import is successful. Also, if I open terminal within jupyter-lab (from the launcher) import is also successful. So import fails only from notebooks (tried from different notebooks).

Tried to reinstall jupyter-lab (“pipx reinstall jupyterlab”), to no avail.

Any ideas? Thanks.