I am having the same issue. I am using 3.1.4 after doing a clean uninstall a few days ago to try to fix the issue. It worked until I cloned the python environment so I could install more packages. When I switch back to default Jupyter Notebooks works as it should. However, default doesn't have the packages I need.
The cloned environment is saved in the same folder as the default python: "C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3-clone" - is that best practice or is there a better place?
Please note my script works perfectly in the python window using the cloned environment.
Any advice? We can't upgrade to 3.2 as we have incompatibility issues with our geodatabase 😞