Reset the lsp _shutdown flag when starting the LSP server.

extensions/positron-python/python_files/positron/positron_ipykernel/positron_jedilsp.py

@@ -216,6 +216,11 @@ def start(self, lsp_host: str, lsp_port: int, shell: "PositronShell", comm: Base
         # Give the LSP server access to the kernel to enhance completions with live variables
         self.shell = shell
 
+        # If self.lsp has been used previously in this process and sucessfully exited, it will be
+        # marked with a shutdown flag, which makes it ignore all messages.
+        # We reset it here, so we allow the server to start again.
+        self.lsp._shutdown = False
+
         if self._server_thread is not None:
             logger.warning("LSP server thread was not properly shutdown")
             return