Judging from the timing that netcat (nc from nmap-ncat-2 package) isn’t installed.
It seems this could be relevant to you. Basically what’s happening is this: we’re using netcat (nc) to check if that port is open (in your case 41861). Looks like in your case, it takes a little over 1 minute for it to decide that it was never opened. This is wrong, because the logs clearly show that it Jupyter did boot correctly. What’s more likely is that we sat in a loop and failed to execute nc for a minute.