You do NOT need to have the hub open in your browser and you do NOT need to be logged in there. 
The node runs, you can close the browser. 

BUT: if an update needs to be installed or if the node needs to be restarted you need to unlock it with your password by logging in once. 

In this case you should have gotten an email that you should update your hub (which is a click of a button and then the unlock) and that an update will automatically be deployed after a few days. 

I hope this explains it?