Hi, this is unlikely to be a problem with JupyterHub, as you’ve realised it’s most likely to do with your file system permissions. Jupyter Notebook/lab may create additional files/directories (e.g. checkpoint files), could that be the problem? Can you paste the output of
ls -lRa
in your working directory?
If this doesn’t help please give us as much information as possible about your system and JupyterHub deployment, and details of how you set or changed the permissions. Ideally provide enough information so someone could reproduce your problem if they wanted to.