I am not very familiar with Jupyter Labs, but is there a time limit as to how long notebooks can run for? It seems as though jupyter labs consistently times out in the middle of my computation. I have double checked that this is not an issue with my code; rather, it seems as though any time I run a computation >15minutes, it stops right around the 15 minute mark! This is happening for me across multiple notebooks. Please let me know if this is an issue that you have encountered before.
No, there isn't any timeout. There is however a memory limit - if you are loading data, then perhaps you fill this up around 15 minutes, and thus dies.
Perhaps you can try a long running calculation which doesn't load much data to verify.