Notebooks sometimes stall until manually reopened

[mat-adamec]

I've noticed lately that:

1. I work on a notebook.
2. I close the browser out of coffea-casa without closing the notebook tabs.
3. I reopen coffea-casa in my browser.
4. The notebook tabs are still open, but they do not run. When I execute them, the cells don't have an *, they don't have numbers, they just turn into empty brackets [] indicating the run has stalled.
5. If I close the notebook tabs and reopen them, everything works fine. I don't need to restart the server for this, just the tabs.

This isn't a huge issue, but it is one I've only noticed in the past month or so, so I don't think it's expected behavior.

[oshadura]

@mat-adamec it could be us developing directly on coffea-casa instance. Sorry for this!
@jthiltges can we please check Flux settings that it is not updating too often, since I noticed the similar behavior with message "Kernel died" when I am trying to update helmrelease with Flux...