After the REST report service renders a report for the first time, the ASP.NET Core process can no longer exit on its own. On shutdown (Ctrl+C, SIGTERM, or stopping from the IDE) the host logs "Application is shutting down...", every hosted service stops, and Main returns, but the process stays alive because the report-rendering queue’s foreground worker threads are still running. In containers it is only ended when the platform's grace period expires and it is killed (SIGKILL), so every stop or restart of an instance that has rendered a report takes the full grace period.