As initially reported in pangeo-data/jupyter-earth#105, I think the jupyterhub-idle-culler fails to recognize that a user may be active via a SSH connection when using jupyterhub-ssh. Is this something we can avoid?
I'm not feeling confident about if we can, or how we would go about it. Very related reading is the jupyterhub-idle-culler's README's How it works section though.
As a workaround, I've suggested visiting the user server via a typical Jupyter UI, opening a notebook, and running something like import time; time.sleep(3600*24*7) to make a kernel stay running, which would block the culler logic.