Having lots of warnings "no such comm"

Hello, I am using Jupyterhub with a Python 3.8 Kernel in a class I am assisting. Everything seems to work, but in my logs I am getting the following warnings (which don’t seem to influence anything crucial as far as I can tell):

[IPKernelApp] WARNING | No such comm: 653ac2b43ab944f8a6bfff9603dc0b7e

The warnings are all of that sort, but with different hashes at the end.
What is causing these issues and how can I get rid of them?

Thanks for your help! Let me know if you need anymore infos.