Following instructions on https://jupyter-contrib-nbextensions.readthedocs.io/en/latest/install.html to install jupyter-nbextension does seem to work on an empty ubuntu container, does not seem to install on our container after we add all the things we add.
This causes the public link in the older interface will not display, the labs interface will still display.

Last known container to work is pr-173, first known to fail is pr-176