Flask Debugging in VS Code with Hot-Reload 🔥 | Theodo
blog.theodo.com › 2020 › 05May 11, 2020 · In debug mode Flask uses a first process (with pid==1) to start child processes that handle connections.If the code below this line is executed by the main process, the debugging port is taken and subsequent child processes can't use the same port and are attributed a random port which prevents connections.