When I open a worksheet with a connection, my connection will be killed in the background due to being idle for too long as per database configuration. This is not immediately visible or known. Attempting to run a query or code block in this worksheet after the session is killed, should return an error in a reasonable amount of time and offer to reconnect to the database.
Instead, the execution attempt keeps going, sometimes for hours, before the disconnect notification finally shows. This has started occurring after the 26.1 update, as far as I can tell