Ipython notebook error

Hi, I’m using Ipython Jupyter Notebook in Digital Ocean droplet and accessing the notebook from my computer through Core tunnel. However, the connection keeps breaking and need to reconnect.

And the browsers shows Connection failed : A connection to the notebook server could not be established. The notebook will continue trying to reconnect. Check your network connection or notebook server configuration.

When I click okay, I can still use the notebook but this keeps happening every 20 seconds and it’s really frustrating for me. I opened the firewall as suggested here (https://jupyter-notebook.readthedocs.io/en/stable/public_server.html), but doesnt help.

Restoring connection for 20ed572d-99de-4981-9b28-acc2b4ba1c03:39cbc9cecb4e4bb98930a08bbac44506
[I 00:23:53.759 NotebookApp] Starting buffering for 20ed572d-99de-4981-9b28-acc2b4ba1c03:39cbc9cecb4e4bb98930a08bbac44506
[I 00:23:58.282 NotebookApp] Adapting to protocol v5.1 for kernel 20ed572d-99de-4981-9b28-acc2b4ba1c03```

Could please enable logging and paste your log (don't forget remove sensitive information):