I observed the same issue while testing on a real device using VS Code. Everything had been working fine, then suddenly I started getting the exact same error:

Error: Flutter could not connect to the Dart VM service.
SocketException: Send failed (OS Error: No route to host, errno = 65), address = 0.0.0.0, port = 5353

There were no relevant setting changes, and the system’s Local Network permissions looked fine.

Not sure about the root cause, but here is what fixed it for me:

• restart the IDE

• restart the device