how to find the browser tab running the jupyter notebook you want to work on:

(1) find the terminal tab running the relevant jupyter notebook server (you may have several)

(2) hit ctrl+C

(3) the server will give you a URL to access your notebooks, copy and paste this into a new browser window and navigate to the desired notebook

(4) answer "N" to the question "Shutdown this notebook server?"

(5) completely forget whatever tab already had the notebook running