Django/Daphne, got NotImplementedError calling asyncio.create_subprocess_exec( under WINDOWS

Question

I am using Django 3.2 with Daphne 3.0.2, Python 3.8.9 under Windows 10.

Trying to call

proc = await asyncio.create_subprocess_exec(
        python_exe,
        bridge_script,
        stdin=asyncio.subprocess.PIPE,
        stdout=asyncio.subprocess.PIPE,
        stderr=asyncio.subprocess.STDOUT,
        )

Gives me following error:

Exception Type: NotImplementedError
Exception Location: c:\python\python38\lib\asyncio\base_events.py, line 491, in _make_subprocess_transport

When serving Django/ASGI with daphne. Under Linux everything runs fine. Serving under Windows with Python runserver also everything fine, Just daphne & windows gives me the error.

Thanks for any help.