I can confirm that I too have this problem on usegalaxy.eu with Interactive JupyTool and notebook.
When I tried to load a previous notebook yesterday (23rd April 2024), then it took hours to see a response, and ultimately the notebook often started in a stopped state. The tags on the right-hand History panel remained grey, neither yellow nor green.
Maybe my problem is that only one notebook at a time by one user is allowed* and I started multiple, so each new one was automatically prevented from running.
*See here:
https://help.galaxyproject.org/t/error-with-rstudio-crashed-and-impossible-to-run-again/12219/2?u=bence.melykuti
Now I shut down the running one. Thereafter very quickly a stopped one started running. I stopped that too. A new stopped one started. This way I could deal with the stopped ones by shutting them down one after the other.
*This post was hidden on 2024-07-12 due to being flagged as spam. Maybe the link triggered it?