Setting the startup folder for jupyterlab & juptyer under windows in jupyter_notebook_config.py

Would anyone please explain why setting c.NotebookApp.notebook_dir and c.ServerApp.notebook_dir in jupyter_notebook_config.py does not stick (even after using all known tricks in pathlib) under Windows, while it’s a breeze under Linux.

Copilot was semi-helpful, but still to no avail.